Ok, so since im not currently making anything, i want to see what this community would like! Please nothing really advanced like voice recorders,3D graphics,ect.
You should specify if you want to make a big or small project.
IMO, an IDE could be an interesting project. It could be a basic editor that let you define templates (Example: generate for statements, def statements or custom blocks created by the user).
Good luck with that project. I made a clone of the battle system before (Friendly Pellet Rain) however I didn't continue with that because I didn't found appealing mechanics to differentiate with the original. Also, the fact that collision doesn't work well with rotated sprites is annoying.
One last thing. You should learn how to create and manage an event queue(For the bullets).