I’ve whittled it down to two, both of them primarily multiplayer. Although I’d only be developing a simple singleplayer version unless I could find others to chip in.
Concept 1: tabletop wargaming.
Each player has a set number of “points” to pick an army. Each different type of soldier costs a different number of points, and can be given extra armour, weapons, etc, all of which affect the points values.
Then you play the game. Like an RTS on a zoomed-in map where you can see the whole map and it’s just one battlefield (if you’ve played the Total War games, you have the general idea).
Most of the game is about choosing combinations of troops, choosing where to place them, and then directing whole units at a time to move around, encircle the opponents, attack, etc.
Most of the implementation effort is making good control systems and decent graphics (in particular getting animated 3d models or 2d grahpics for each soldier, and animating them individually so that your soldiers don’t all move in locksetp, which looks really stupid).
NB: Working out the points values would be easy, I’ve done it many times before and worked with lots of different variants.
1p mode: play against simplistic AI (probably just tank-rushes the biggest enemy unit, repeat until match is over).
2p mode: pairs of players face each other.
Concept 2: Smash TV remake
Smash TV has a simple premise: you’re going to die, sooner rahter then later, through sheer numbers of enemies. THe game is made up of rooms, and as soon as you enter a room all the doors lock and literally thousands of enemies spawn all over hte place. If any hit you, you die. You have infinite ammo and jsut need to try and survive. There’s a set number of enemies that spawn per room (but usually you have to survive for up to a couple of minutes just for them to stop spawning!) and once they’re all dead the doors open again. You have to navigate your way around a maze of these rooms; one false step means two extra rooms to clear!
1p mode: obvious
multi-p mode: as soon as one player leaves a room, all the others are dragged with him (co-op play), or each player can visit separate rooms (competitive play). Aim is just to have the highest score by the time you die!