Well, if you add a separate editor’s pick section, then it may not be necessary to gate off submission of games. If you do have a review process, you might need some kind of policy about what makes a game good enough. If it’s only determined by an admin’s personal feelings, then some people might feel like it’s unfair if their game is rejected.
I’m not sure of the best approach here because I do like the idea of a curated gallery. However, somehow the original Gamebuino gallery had a decent average quality, possibly because it required (a small) extra effort by people to figure out how to add games, which might have made it self-moderating.
I think that having a gallery open to anyone may encourage people to post their games, and a separate editor’s pick section can provide a curated list. I also don’t think that forum posts alone are good for posting games because games get buried in other posts and game posts only have the title instead of screenshots. I’m guessing a lot of people only play the games on the original game card and don’t search for new games, and those that do would only look at the games gallery. Perhaps only a small percentage would be looking for games on the forums.