Everything is done through key hints / prompts / tutorial.
At any moment, different actions appear on the screen, with the keys needed to execute them underneath.
All you do is look at the options and pick the best ones.
So, I still need the specifics of your objective and gameplay. But this general mechanic of “actions appear + unique button to do them if you want” has potential.
Touchscreen? These prompts are simply clickable buttons on the screen. (Like my sister’s idea about just presenting options and clicking one.)
Gamepad? The same idea. But now the prompts will also designate who must press it => just a player number. (And the prompts aren’t keys, but just symbols+colors.)
Multiplayer? That’s automatically covered. (With more players, you can simply add way more prompts, so you can’t even do it all with your own hands.)
Related idea: a game to learn touch typing, mostly for kids.