Stick to one or two graphical themes. If you don’t have enough time to make all the graphics you want, then limit yourself so your worlds don’t look empty (like mine)

Don’t assume everybody knows whats going on. Make your rules apparent. And when the rules change, also make that apparent. For instance, I had a point in the game where you get a yellow arrow which was meant to give you the double jump ability, but some people didn’t realize this. I put the blame on my shoulders, I should have told them better. Granted, I made it so you couldn’t leave the room without using the double jump, but I should have said “HEY YOU GOT DOUBLE JUMP NOW!”

Make your games tight. Even now as I go back through my game, I can see where it would have been better if it were a little smaller and tighter.

I’ll have more thoughts as they come.