Collection of Tower Defense Features, Ideas, Tips and Review.
Attention to TD Game Developers!
Below are some useful information for tower defense developers to learn from others, such as types of features that they have implemented to make their game enjoyable, interesting, unique, relaxing, and re-playable. If you have some good stuff to share, post a comment here and I’ll add into this page!
Tower Defense List
A001 – Ant Buster TD
B001 – Bloons Tower Defense 3
D001 – Desktop Tower Defense
F001 – Flash Element TD
G001 – Gemcraft TD
M001 – Mushroom Farm Revolution Tower Defense
P001 – Protector TD
W001 – Wacraft III
Z001 – Zombie Apocalypse Recycled!
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NUMBER OF MONSTERS PER WAVE
– You can have invading monster coming in masses, average or few.
– Basically, masses are usually for weak monsters which is easily killed by players tower.
– Few are usually for bosses which comes as a single unit, pair or triple.
Number of waves per map/world/game
– Endurance/Uber/Unlimited wave have more waves within a certain map to test player’s endurance level.
MONSTER SPECIAL ABILITY
1. Flying Ability
2. Spawn Mini Monster
3. Tankers / High-HitPoints HP
4. Effect Immunity
5. Road Runners / F1 Racing
6. Shield + Regeneration
7. Life Regeneration
9. High Armor
10. Element Types
11. Armor vs Weapon Type
When monster have lower HP, they might run faster as they are panic for their lives!
[D001] Flying Monster
In Desktop TD and Flash Element TD, the game features flying creatures which can only be attacked by air tower or arrow tower. Since they are air units, they could either travel directly to the destination without following any maze/road.
1. Build anti-air tower that specializes in attacking air unit.
[D001+B001] Spawn Mini Monster
In Bloons TD and Desktop TD, it has a particular creep that respawns 2 or more monster once the parent is being killed. The spawn creep can jump to the shortest road. To balance this ability, the 2 particular creeps would have weaker stat than the parent and unable to jump across to other road if there are no obstacles. To counter this, one could:
1. Use Splash attack against multiple creeps.
2. Freeze the monster and use any attack to break the ice. This is to prevent them from respawning within its parent.
[M001] Tankers / High-HitPoints HP
Tankers are known for their massive hit points that would make it difficult to be killed in few shots. This is commonly applied to all tower defense games whereby each wave increases their HP. To balance this ability, the developer controls number of waves per game. To counter this, below are 3 solutions:
1. Implement delay towers for this monster type [Teleport/Stun/Confuse/Slow]
– Teleports the monster to the entrance. This allow towers to attack them again.
2. Implement probability effect death [Instant Death/Plant Bomb]
– This helps to reduce the burden of the main towers to deal damage on the remaining monsters.
– Plant Bomb sets a bomb if a monster has 50% HP lower, explosion deals 50% damage to nearby monster.
[M001] Effect Immunity
Monster have effect immunity to balance out most effect towers available in game. This is to prevent player from creating only a particular type of tower to win the game, which makes the game boring since strategy of using variety of effect towers is not involved.
[F001] Road Runners / F1 Racing
Road Runners allows a monster to take sharp corners easily to reach their destination faster along. They are renown for fast movement compare to normal monster speed. To balance this ability, these monster equip with light armor in order to move fast, thus take more damage per hit. To counter this:
1. Have tower upgrades for shooting speed [reduces reload time], increase tower damage and range.
2. Build slow towers to reduce road runner speed.
[W001] Shield + Regeneration
Shield Regeneration allows a robotic enemy/enemy to regenerate their shield when they are under attack or without any interferences. To balance this ability, the shield only recovers itself but not including the enemies base life [Gunbound Idea]. To counter this ability, there are 4 solutions:
1. Create shield piercing tower that pierces through the enemy shield to deal damage.
2. Create an EMP tower that cancels out enemy shield by a certain percentage % per hit.
3. Create a tower that deals extra damage to enemy shield but less on their main life.
4. Create an aura tower that disables unit from regenerating shield if they are within vincinity.
[F001] Life Regeneration
Life Regeneration allows monster to endure longer after they are severely injured by towers or they regenerate life when they are hit by an element that are strong against! To balance this ability, if they are not under attack, they could not regenerate life. To counter this ability, there are 2 solutions:
1. Create poison tower that deals damage for few seconds on a particular unit.
2. Create splash tower that deals splash damage to nearby units.
Invisiblity allows monster to avoid absorbing damage taken during their invisible state as they travel to their destination. To balance this ability, invisibility will only be take place for few seconds before reappearing full view for the next few seconds. To counter this ability, there are 4 solutions.
1. Create a special tower that can attack monster in both visible and invisible states.
2. Create a detector tower to view invisible units to allow other towers to engage them.
3. Allow player to perform tower research to allow all towers to detect invisible units.
4. Purchase an item for tower to allow them to view invisible units within range.
[G001] High Armor
High armor monster greatly reduces the damage absorbed from tower attacks. To balance this ability, heavy armored units would be slow like snails as they travel to their destination. This allows towers to get a few extra shots on them. Here are solutions to counter this with strategy instead of brute force fire power:
1. Create reduced armor tower whereby its bullets reduces a monster armor temporarily or permanetly.
2. Create an aura tower that reduces monster armor temporarily.
[M001] Element Types
There are 2 category of defense to choose from. 1 is determined by the element, and the later is weapon vs armor. Element refers to a specific element strength and weakness. For example: fire is weak against water, but strong against earth. In this example, I have shown 3 elements: fire, water and earth. There might be some reasonings behind this such as fireman extinguish fire using water, and fire can burn trees/earth. This concept can be applied to a particular monster element strength and weakness too. Element concept can be seen applied in many games such as Survival Project MMORPG, Pokemon, Mushroom Revolution, Gemcraft, Warcraft Element TD. Here are some basic elements you can use for your game: Fire, Earth, Water, Wind, Thunder, Light, Darkness, Periodic, Nature, Ice, Metal, Physic, Ghost-Spirit. To balance element ability, a particular element should be strong against an element or weak against another. For example: Fire – water weak, strong earth, Water – earth weak, fire strong, Earth – fire weak, water strong.
[W001] Armor vs Weapon Type
In Warcraft III, each wacraft unit has different types of defense.
Normal (melee) – extra damage to Medium armor / reduced damage to Fortified armor.
Piercing (ranged) – extra damage to Unarmored, Light armor / reduced damage to Fortified, Medium, Heroes.
Siege (artillery) – extra damage to Fortified armor, Unarmored / reduced damage to Medium, Heroes.
Chaos (summoned) – Chaos attacks do full damage to all armor types.
Magic Damage (spellcasters, air units) – extra damage to Light, Heavy armor / reduced damage to Medium, Fortified armor, and Heroes.
Magic Damage (spellcasters, air units) – 66% extra damage to ethereal / zero damage to magic-immune.
Hero – Hero attacks do reduced damage to Fortified armor.
TOWER DEFENSE FEATURES
Gambit system is introduced in Final Fantasy to automatically controls the actions of character.
This system can be implemented in Tower Defense to allow player micromanage their towers more efficiently against invading creeps. For instance, order tower to focus their target against: [Vector TD]
– fastest creep / strongest creep / creep that is nearing their destination
– slowest creep / weakest creep / creep which is weak against the tower element
– target boss / target a specific monster / order tower to do splash attack at a specific area.
Also, towers could be given some orders similar to Sonny 1 and Sonny II.
– agressive mode : Full offense, constantly deal damage against enemy without hesitating on its condition.
– supportive mode : A mixture of offense and defense.
– defensive mode : Provide mostly support such as heal, cure, remove negative buff.
Allows user to have better controls over the game such as implementing short cut keys like Gemcraft, implement multiple tower selection and upgrading a few simulataneously. Also, allow the selected of multiple towers have the same order.
MONEY / RESOURCE / MANA SYSTEM
This is to allow players to purchase item using one of the resources above.
Whats the source of income?
Kills – Each kills provide some cash/mana/resources
Resource – Construct building to provide resources. [Power Plant, Farm, Mine, Factory, Housing, etc]
There are a few ways to calculate the score during the gameplay and after the player completes the game.
Below are a few samples:
Money – How much money left in the bank? [F001]
Towers – How many towers constructed? [G001]
Kills – How many kills achieved with stream of wave poured in without delay? [G001]
Time – How fast you click next wave to earn more points? [G001 + M001]
Resources – How much resources were generated? [Z001]
Tower Efficiency – How efficient the towers during battle? [Z001]
Lost – How many life lost? [Z001]
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[Mushroom Revolution TD Review]
– Randomly rewards an accessory for each 5 monster waves sent into the map.
– However, each Gomphus Tower only has 1 accessory slot, and can’t be change once its equipped.
– Different appearances for each animated mushroom. But difficult to tell their effect type.
– Has lots of special effects at your disposal against the invading hordes of pokemon-like monsters.
– Upgrading non-pure gomphus/tower increases special effect probability for success.
– Applies gem combination concept from Gemcraft. However, these gems can’t be switched.
– Monster has random strength,weakness and immunity with increasing HP and cash as wave increases.
– Allow to clear obstacles such as trees/cactus before building Gomphus Tower on that location.
– Each map rewards different medals based on World achievement, and rewards skill points.
– Skill points use to upgrade starter gem and accessory, increase tower dmg, max hp, wave delay, earn cash.
– Has a Valentine Map that lasts for 7 days, starting on the eve of Valentine’s Day Feb 13.
– The map is huge, so players are required to scroll/browse the map by using WASD keys or mouse cursor.
– 10 World Map, each with unique monster route such as roundabout, circle, twist, parallel road.
Mushroom Revolution Gameplay
– Allows user to speed through the game by clicking 1x/2x/3x speed.
– However, speed modifier works on certain browsers such as Firefox, but not well on Opera.
– Speed will slow down due to lag when there are many towers place and many monsters within the map.
Monster Next Wave
– Allows user to check only the next wave monster characteristic by hovering the mouse on “Next Wave”
– Does not show a few next waves of monster that will be invading.
– [Idea] Add a feature such as telescope which requires player to purchase to view other next waves?
– Does not have option to allow user to spawn monster once all monsters are killed.
– Does not have timer for user to control monster spawn.
– Player is able to check monster stats by clicking on the monster itself when they are moving on the road.
Variety of Maps
– Has 10 different map routes. Some has roundabout, 2 path closely converge together.
– Allows user to clear trees that is consuming a specific spot, to allow a tower to be constructed there.
– Does not have money interest per wave.
– To pause game, simply open the Menu Window.
– Allows user to change game quality: LOW/MEDIUM/HIGH
– Does not have difficulty settings such as EASY/AVERAGE/DIFFICULT/IMPOSSIBLE
– Does not have option to choose certain map, requires user to complete 1 map given by the game at a time.
– Has save/load feature since it includes the .sol data on players machine.
– But, the save load does not work in-game but outside the World Map.
Mushroom Revolution Score Points, Rewards, Skill Points, Upgrades, Medal
– There are 3 types of medal, Gold, Silver and Bronze. Each has different score points requirement.
– These 3 medals is based on how much points you have achieved in the World Map.
– The points are equal to the total monster HP for all waves within the map + remaining HP in-game.
– However, basing on monster HP for points leads to more waves to increase the total points for other world.
– This makes it tiring/grinding waves that most player dislike. They would like short challenging game.
– Basing on other factors for score points is one of the solution instead of solely relying on monster HP.
– Such factors that can be consider are total money in bank, no. of towers, tower efficiency, etc.
– When a player completes a map/world, they will be rewarded some skill points [SP].
– The skill points rewards are based on the medal achieved. Gold rewards 6 SP, Silver 4 SP and Bronze 2 SP.
– There are 6 upgrades: starter gem and accessory, increase tower dmg, wave delay, earn cash and max life
– Each upgrade requires different amount of skill points.
– This upgrades help you complete a map much easier and to score higher points.
Mushroom Revolution Tower Details
– Does not have anything special to place on the road to help tower.
– For example, Gemcraft: Moat | Bloons 3 – Monkey Glue / Road spikes / Pineapple Bomb
– Tower does not support other tower in terms of damage/money/speed/range like Onslaught TD.
– However, there are individual towers that support in their own ways: Teleport, Confuse, Stun, Poison, etc
– Selling towers seems to be less worth because selling loses 75% of the money invested on a tower.
– For example: Level 6 Tower with upgrades cost $9500, but selling them will be $2200.
– Pure Tower: Requires all 3 slots to have same gem type/color.
– Non Pure Tower: Requires 2-3 slots with different gem type/color.
– Gem Combination: Combine gems to create tower with special effect or pure damage.
– There are 20 different types of combination for special effect non-pure towers.
– 5 Types of Gems: Red Ruby, Blue Pearl, Yellow Topaz, White Diamond, Green Emerald
– Gems Cost: Cost of each Gems are same: $200.
Neutral Towers: Has 25% weakness to all elements.
Pure Towers : Has no weakness, and deals +100% extra damage to a specific element.
Primary Offense Towers : Double Damage, Triple Damage, Splash, Big Splash, Machine Gun, Germinate.
Secondary Offense Towers:Sniper, Poison, Splash Poison, Instant Death, Plant Bomb.
Money Towers : Wealth, Money Steal.
Delay Towers : Stun, Teleport, Confuse, Slow, Splash Slow.
Endurance Towers : Life Plus, Life Steal.
Tower Strategy Special Effect
Instant Death, Plant Bomb, Teleport
– Reduces the overload/burden for damaging towers to kill monster for each wave.
– Damage towers and delay towers can focus on the remaining monsters which has escaped this two.
Stun, Confuse, Slow, Splash Slow
– Allow nearby towers to get extra shots on monster before they move away from tower attacking range.
Triple Damage, Double Damage, Germinate, Machine Gun, Splash, Big Splash, Sniper
– The main towers that deals plenty of damage to monster who are moving to their destination.
Poison, Splash Poison
– Reduces monster HP overtime by -1.8% HP/sec. Rough calculation.
Life Steal, Money Steal, Wealth, Life Plus
– Allows player to endure massive waves. More money = more Towers, More life = increases survivability.
Mushroom Revolution Animation/Graphics
– Cute looking mushrooms towers with funny face appearances and colors.
– Nice explosion effect on monster when they are killed by a tower.
– Has variety of monster appearances.
– Has a label to determine their level. Example Level 6 below the monster.
– It seems difficult to place tower not knowing the constructable spot – no grid tower placement aid.
– Towers have different appearances in faces and color, but difficult to differentiate between their effects.
– Grows stronger by waves in terms of immunity and hit points [HP], and rewards more money.
– Also, their damage against player life becomes more severe. E.g. wave 70, a monster removes 7 life.
– Randomize strength, weakness and immunity to special effects.
– Has different kind of weaknesses and strength: Fire/Thunder/Earth/Wind/Water
– Each monster waves are unique in terms of movement speed, spawn in masses or in few.
– There are boss monsters with higher HP than ordinary monster. but money reward seems to be random.
– Monster spawn with random patterns.
Sound Effect and Background Music
Does not have mute for sound effect
– Has a mute feature for background music and sound effect.
– Does not have volume controller for background music nor sound effect.
– Has a low selection of background music.
– Unable to select a particular background music to listen.
– The word “Action” each time the user starts a map is pretty annoying.
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[Gemcraft TD Review]
– Applies gem combination for special effects and extra damage.
– Has 9 save/load game slots.
– Implements mini badges that rewards extra points when you win a particular map.
– Uses mana instead of money for purchases in-game such as mana pool upgrade, moat, tower, gem, etc.
– When a player successfully completes a few map with Gold Frame, they unlock secret maps.
– Each map has its own score points, thus allowing players to replay the same map to achieve higher points!