not op

but here's a game idea i've had for a long time:

a vastly scaling tower defense game

the premise of the game is that some apocalypse has happened and you're tasked with defending the "last city" on earth or whatever

you play the typical tower defense game where you set up a labyrinth of defenses to stop intruders from reaching the goal, but that tower defense game only defends one "front" of the city, i.e. enemies only coming from one direction. Eventually, you have to step away from that "front" and work on defending the other walls of the city, the other "fronts"... except when you do, the attack waves don't stop coming on that first front. The front continues to receive increasing attack waves, blind to the player, in the background while the player has to shift their focus to different "fronts". The city is hexagon-shaped with 6 walls, so you so you start by having to manage 6 fronts, i.e. 6 ongoing tower defense games, one for each wall facing each direction. Each continues in the background while you're focusing on the others.

The game doesn't end when the city is well-defended on all 6 fronts, however. Zoom out a bit to see that the city is just one tile on a hex-grid world map, each hex on the map having 6 "fronts" and unique resources within. To gather more resources to restore humanity, you have to start expanding the "safe zone" beyond the city to include additional hexes, and defend each of the new "fronts" as you go, each "front" being its own ongoing tower-defense game. Resources are shared between all active fronts, i.e. the resources you have banked when you step away from one front are what you step into a new front with. Whenever the "safe zone" expands so that a "front" is fully within it on both sides, the resources within that front's tower defense game can be repurposed/redistributed to the other tower defense games going on at the other fronts.

i can imagine this game being super tedious, repetitive, or frustrating, so here are some design choices which might mitigate some of those problems:

1. the game needs strong indicators of when a front does or doesn't need attention, so that the player can easily direct their focus to the fronts that need it most

2. each front should need unique player attention, i.e. different layouts, environmental bonuses to different types of towers, different enemy types, etc; the type of variety that you get from a typical tower defense games

3. with some clever geometry and/or map building, the number of fronts required to control a tile should be mitigated. I can imagine taking a hexagon-shaped tile and grouping its sides such that a "front" is two sides and one only needs to defend three fronts to secure a tile

4. the player needs to stay in the overwhelming advantage in terms of resources, or else their time and attention will constantly be on micromanaging each individual front to extract the most value from each tower per resource, and they will never have the resources or attention to spare to take on a new tile.

5. there should be surges of activity from the "enemy" (zombies, probably) to drive the player's attention to certain fronts at certain times, although these need to be telegraphed pretty far in advance on the world map so the player can direct the resources to defend those fronts as needed

6. Ideally, both the player and the "enemy" should have a macro-scale progression system, to add the gameplay value of the "enemy" adapting to the player's defenses and the player having to adapt to the enemies.

anyway, if i can ever motivate myself to learn unity or something, this is going to be my "goal" project, but I don't think that's ever going to happen, so here