Name a game where you can become increasingly powerful without relying on levelups or equipment/ability upgrades.
Tetris
>>345431583
dwarf fortress
UT 2004.
How else would you power up? By just getting new abilities or something?
If that's what you mean, Devil May Cry
Melee
Any multiplayer game.
Dota.
As you play more games, you become more skillful at it, and thus more powerful.
>>345431583
RTS and Grand Strategy games
any rts
>>345431583
That depends what you mean by equipment upgrades.
Potentially STALKER
>>345431583
Agar.io
>>345431715
If a game has a high skill ceiling but doesn't have any levelups or equipment/ability upgrades, you get more 'powerful' by learning and getting gud.
>>345431583
monster hunter
>>345431583
Giants Citizen Kabuto to some extent.
>>345431583
Ignoring getting new weapons, Serious Sam
>>345432508
>Ignoring getting new weapons
That's literally how you become more God mode though
Rocket league
>>345431583
Gothic 2
The usual way to advance in power is through better gear and leveling however if you git gud enough you can take on high level enemies with starting gear. There was a video around where someone rekt an elite enemy with just starting shit tier gear and pacience.
Spelunky
If by that you mean games with a high skill ceiling that take quite a while to get good at.