Game design document
Core Concept
A singleplayer Top down/ isometric shooter game where you kill enemies to survive waves, earning an upgrade card each wave. These upgrade cards can be applied to your gun in different combinations and with different cards to form specific builds that you want to play with. The difficulty and types of enemies will increase with the wave level, for example spawning a boss at wave 5. Waves will continue until you die or reach a high enough wave to be considered winning and it will grant you upgrade points that will increase overall stats such as: luck, health, fire rate or even more upgrade card slots. These upgrades apply to your character or gun and will boost the effect of the upgrade cards and allow you to play levels faster.
A key upgrade/ mechanic/ feature will be the ability to transform your gun into a turret and play as immobile sentry. You will benefit from automatically aiming in this mode, however you cannot move to dodge attacks and may die easier, tower defense like.
Another key feature/ mechanic is a currency exclusively dropped from bosses, that resets every level, and allows you to buy any upgrade card in the game. The shop will probably be limited to only appearing a few times per level to prevent fully avoiding the rng aspect of the game.
Gameplay mechanics
- The character stays centered on the screen but the environment moves around it to emulate movement and is controlled with WASD directional controls.
- The gun is aimed with the mouse and it pivots around the character. Left click to fire it
- You spawn with one medkit/ repairkit, and can pick them up as random drops from enemies. They can be used once per item to heal your character and are used up in this process.
- There will be different levels each with different incremental waves and enemies. Waves get harder the higher they are with stronger enemies spawning more frequently. Additionally there will be certain even harder boss enemies that could include cutscenes and lore for the game, as well as providing the currency used to buy upgrade cards in the shop.
- There will be special event waves such as: a swarm of enemies that drop a small amount of boss currency but they have a high health pool, and will despawn when they get across the screen. This means you have to either slow them down, kill them fast enough or lose most of the possible reward by letting them just leave the wave.
- The shop will appear on certain waves/ can be summoned to access every upgrade card in the game at a cost of the currency dropped by bosses or special enemies. This allows players to avoid some of the luck needed to build a specific build while still needing some skill to earn the currency in the first place.
- The end of level upgrade points can be used in a skill tree to unlock many useful attributes to boost your character,gun and enemies. These upgrades will include: additional upgrade card slots, more healthpoints, increased currency drops, higher fire rate.
User Interface
The UI will be simplistic and intuitive to understand. The upgrade cards will be similar to these cards from the game “brotato” by Blobfish Games. The rarity of the item will showed by its colour, an fun image of the upgrade, title of the upgrade and the attributes the upgrade card effects. Similar to every other upgrade game with colours for the rarity of the upgrade.
Image posted by AdamsIdeas (2022) on steamcommunity.com. Available at: https://steamcommunity.com/sharedfiles/filedetails/?l=spanish&id=2896126855 [Accessed 2 Oct. 2025].
Not many buttons probably only a setting button and home/pause button which could all be hidden within one menu.
Character:
There will be a small amount of character customisation in the main menu, where you can change what the character is wearing and what colour your clothes and skin are.The character design will be simplistic, a round torso and head, with round cornered rectangles as limbs. The customisable hats and clothing would then go on top of this. These cosmetics could either be bought or rarely dropped from an enemy that spawns with the cosmetic equipped to them
Similar to the character design from the game, Binding of isaac.
Image by Rappenem (2020). Finally finished respriting every Isaac character! [online] Reddit.com. Available at: https://www.reddit.com/r/bindingofisaac/ comments/nxlweu/finally_finished_respriting_every_isaac_character/ [Accessed 21 Dec. 2025].
Level Design:
Cave/island (small/claustrophobic spaces) which could be upgraded/extended with in-game earnt currency to allow for more room for killing. For the cave idea of a level it could be a relatively dark small room, of which the enemies either spawn from a timber frame supporting the roof with a dark room behind it, which could eventually branch out at a higher wave or be purchased to increase room.
Art:
Simplistic art style, almost cartoonish, but not pixelated. Smooth with flat colours, with an outline. There will probably be minimal use of gradients: because if a colour needs to change it could just be separated into another shape displayed on top of the previous creating a separation in the colours.
For example a map from the game Bloons Tower Defense 6 , shows my idea of detailed but simplistic style. Image from Wiki Contributors (2021). Monkey Meadow. [online] Bloons Wiki. Available at: https://bloons.fandom.com/wiki/Monkey_Meadow [Accessed 23 Dec. 2025].
Audio:
There will be sound effects for taking damage, ui clicks, large enemies spawning, firing and many other sfx. The music genre would probably be fairly ambient and calm towards the beginning and also in between waves. Then while being attacked or in boss fights there could be ramping in intensity and speed combat music, that helps build the tension during waves or bosses.
Technical specs/ Platform:
There will only be PC support because the target demographic mostly uses computers.
Due to the minimalistic art style the game could probably be played on almost any pc, though higher waves with many enemies could reduce performance on lower spec devices.
Example minimum specs::
- OS : Windows 10
- PROCESSOR: 2.33GHz or faster x86-compatible processor, or Intel Atom™ 1.6GHz
- MEMORY: 512 MB RAM
- STORAGE: 150 MB available space
- GRAPHICS: Integrated
Monetisation + marketing:
The game will be a low price of around ~£2 as it is a relatively simplistic game and that price suits the indie/ small game genre. The marketing strategy will be to use social media to promote the game and attract players and also uploading the game to steam and appearing in the upcoming/new game tab will be a good advertisement. However the new game promotion will only be a short term boost in players and therefore other strategies will need to be used for long term sales. Substantial game influencing micro transactions will be avoided but there could be a shop to purchase cosmetics that you don’t want to wait to randomly unlock from playing the game.
Quality assurance:
The game will be tested by the developers themselves initially, then when possible released to some play testers to find and report bugs within the game. In-game performance should be fairly high constantly, easily staying at 60fps. This is because the simplistic artstyle does not require heavily resource taxing things such as ray-tracing or a large render distance. The only time the game could lower in frames is in later levels and waves, if there are many enemies and projectiles filling the screen, each possibly splitting into multiple more projectiles and smaller enemies, the game could possibly lag. However if the bugs are found and entities are optimised the game should never drop in performance.
Story:
You are a special agent employed by a secret company with highly advanced tech, and are sent to the island/cave to clear out infestations of monsters which the company had created with failed experiments.
The company used these remote and isolated maps to test out weapons that created and turned people into monsters.
Word got out that there was monsters in these places and people started to wonder how these creatures could come into existance.
To keep the company and their projects secret. They developed advanced modular and upgradable guns to clear out their messes.
It is your job to use what they have given you to clear out the monsters or die trying. When you do succeed, the company considers you a useful asset and reward you upgrades to help you clear out more maps.
Unfortunately the company did a lot of testing and your the most promising agent, so you have many maps to clear.
There will be a main introductory short cutscene at the start of your first level, then lore will be discovered with bosses and dropped items from the waves. Additionally completing levels unlocks more cutscenes which reveal slightly more about the Company and its testing each time.
Primary Research analysis:
This first graph reinforces the survival round based idea and because 38.5% (5) people are interested in story based games, lore and story gathered from gameplay and cutscenes will be imperative.
Clearly the majority of the playerbase will be pc so there will be no console support.
The majority of people do want multiplayer, however this is hard to implement and many people will still enjoy single player though they prefer multiplayer.
Many people agree that upgrading your loot and unlocking new abilities will be a fun gameplay reward and possibly increase the replayability as you want to play another round with your new abilities but unlock more to try out another time in the process.
This reinforces the game idea again with killing stuff being a 23% most enjoyed factor. Further more learning story from cutscenes and gameplay will attract players to play and learn more as it is the most enjoyed feature at 30.8%.
Loot boxes and micro-transactions will be avoided as it encourages players to waste money for large gameplay buffs. However there may be a cosmetic shop for skins to buy with real currency, but this will be to support the developers and has no effect on gameplay besides looking cooler.
There is a near 50% split about whether a system should be complex or simple, therefore the game will stay in that middle area, where you can make advanced statistical changes if you are a min-maxer or just simply switch out the cooler cards if you are a more casual player.
A cartoonish, stylised art style will work as there is a fairly even split between the 4 options however stylised does seem the most popular.
Most people do enjoy leaderboards and ranks, which is possibly a good thing as it increases engagement and creates a sense of community despite being a single player game. Competiveness makes players yearn to grind and be the best and therefore a leaderboard system on time or max kills will be effective at increasing replayability.
This could be implemented with the higher levels/waves, the difficulty scaling could be changed either by the player or just as you progress the difficulty is harder. Additionally there could be modifiers such as hardcore/ Infinite life for different peoples enjoyment. Furthermore the build you create to pass through the waves also controls your difficulty as if you find something incredibly overpowered you have the choice to blitz through the waves or stay with your current build.
This shows that a social media account for the game would be a useful marketing technique as 70% (9) of people look or come across new games on social media, secondly uploading the game to steam and appearing in the upcoming/new game tab will be a good advertisement.
Design Log:
Only one major change occured after the feedback from the form. Originally the game was planned to have no storyline as it was just a shoot and upgrade game. However the Form showed multiple times that story and lore is wanted and entertaining. Therefore I created a suitable storyline and lore progression to match the games theme.
Other than that change, no major deletions or additions where made, I may have re-worded some areas but mostly just added more information slowly overtime.