I search and try out a lot of open source games. The ones I pick to "restore" are based on my whims. Two criteria do impact that, if the game is two player simultaneous and could be controlled with a joystick and 8 buttons and if the game has achievements. The later is for Gamerzilla support. The former is for the arcade machine.
If people find a game that is broken or could use an update, you could always let me know.
Edit: I do try to contact the original creators. I've talked with the creator of Mojotron, Lady Bug Love, and Fight or Perish. Shippy 1984's creator never responded. For Fight or Perish I was sent the unreleased 0.6 code. He added floor tiles which I already did. His could have different tiles in the same map but I decided to leave my approach of one floor tile. He had music but hadn't gotten permission to use it yet so I didn't put that in.