I envy your position
I've too many projects on the go and not enough time to work on any of them! One idea I've had for quite a while (but haven't started yet) is an Amiga version of Hokra. It's a party game (part of the Sports Friends bundle) and a very simple concept, but a lot of fun to play. It doesn't really lend itself to single player as it is, but it could be possible to take the vague idea of keeping a ball inside certain coloured areas for as long as possible and combining it with a scrolling infinite runner to get a scorable, single-player game.
If you don't do it, I might get around to it some time around 2025