The 'Cool Shit' method of game design

For this game I have been using a (probably not original) game design system I call the "cool shit method".

Basically, you start by thinking about specific situations and feelings you want your player to experience, and then work backwards from that to derive gameplay mechanics and design pieces. 

For example, do you want your player to feel the tension of an enemy approaching closer and closer while you fumble to reload? You could make a horror FPS with slow player movement, powerful but slow enemies, long reloads, possible reload minigames (to add the tension of potential fuckups), etc etc. 

Do you want the satisfaction of watching a well-oiled system operate by itself? Perhaps make a simulation game, with lots of highly-visible activity and complex but relatively stable systems, with lots of automation possibilities for the skilled player. If you want the excitement/fear of a previously-well-oiled system suddenly completely falling apart, consider adding negative feedback spirals, exponential disasters (c.f. Dwarf Fortress tantrum spirals), etc etc.

Some of the original "feelings" I was keen to create in particular for this project are:

• The satisfaction of watching a well-built defence be tested by a huge amount of enemies
  • This is a classic 'feel good' factor for almost all zombie & tower defense games
  • In my game, this is expressed by:
    • Zombie scale and behaviour - "swarm" feeling essential. Performance improvements to improve zombie numbers are high on my priority list right now.
    • Ability to construct chokepoints, heavily fortified selective areas, and other generic tower defense gameplay features
  • Inspired by games like: Bloons Tower Defense, They Are Billions

•  The grimness of having to make hard choices 'for the greater good', eg letting civilians die to save your economy
  • In my game, this is expressed by mechanics like:
    • Some defences (machine guns, landmines) being capable of accidentally killing large numbers of civilians
    • Sprawling maze-like levels make it almost impossible to save everyone, requiring prioritization of resources
    • *Upcoming*: VIPs being implemented, forcing you to make decisions about how much 1 VIP's life is worth
  • Inspired by games like: Frostpunk, DEFCON, This Is The Police

• The helplessness of watching a civilian who is a hairs-breadth from escaping, make a bad decision and end up as zombie food.
  • In my game, this is expressed by mechanics like:
    
    • Civilians are mostly autonomous and can only be very loosely directed by player decisions
    • Civilians don't automatically pathfind to safety, they mill around helplessly on their own
    • Civilian AIs panic in the face of zombies. Even if an escape route is in sight, a civilian will blindly flee from the nearest zombie, potentially dooming themselves
  • Inspired by games like: Atom Zombie Smasher, Lemmings

• Creating an emotional attachment for a part of the city, then watching in horror as it gets torn through by zombies
  • I think I am failing to achieve this right now, chiefly because of how generic and uninteresting the city tiles are, making all parts of the map feel pretty much interchangeable.
  • This is why the game has the tile-placing city-building mechanic, to try to make the player feel attachment and ownership for their city
  • In the future I want to:
    • Have more variety for tile textures, allowing the player to mentally picture different districts/areas as being seperate
    • Have cosmetic upgrades for tiles with minor gameplay functionality but big 'looking cute' functionality. For example, building a hospital could buff nearby civilians, or building a nice park might boost the number of civilians spawned on the tile
  • For me, the absolute crowning achievement of this goal would be if a player chooses to make a suboptimal gameplay choice based on personal attachment to the city they have built.
  • Inspired by games like: Dorfromantik, Dwarf Fortress, SimCity "Disaster" events

There are plenty more smaller 'moments' I want to create with my game, but these were the original ones that guided my very early design of the game (right down to the genre choice)