This is really cool! I actually had a similar idea, but ended up going with something else for the jam. You executed it way better than I could have anyways! I haven't managed to beat Jump Man (yet), so I haven't seen the bonus game, but the other two games are very nice! I do wish you could control both characters at the same time though, as others have mentioned. Would be a lot of fun as a co-op multiplayer game. Another suggestion would be making it so you have to press B to regenerate your shield in the space shooter game; that way you wouldn't just be able to have the one guy stand on the A button the entire time.
Overall, really cool concept executed really well!