Let's say the game is an an image that gets posted. You paste the submitted image into MS Paint, then you can only manipulate it with the tools in the program, and the ruleset provided by the game's creator. Would this be allowed, or is it too far?

I probably wouldn't actually try to do this, but I'm curious as to if it's technically allowed.

to make a game in ms paint is possible, I myself want to make such a game but not on jam.

That's totally allowed! That's such a unique idea!