I am making a game where everytime you attack the enemies get slightly harder
I'm making a puzzle game which the more moves you do, you get less points to go the the next level.
a small rpg where the less mana you have you have more areo of effect
flappy game where whenever you pass a wall your score get lower
You're a store manager, where the less things cost, the more you can sell (and you try to sell your entire stock)
a game where you use your hp to buy skills
A racing game, where you try and toss your cargo onto the competition to lighten your load and go faster (and make them go slower!). Only, they're trying to do the same right back at you.
a top down shooter, where the less ammo you have, the more damage you do
A platformer where player can shrink so the less place before is now more than enough to explore
A 2D shooter where shooting hurts the player