Do you know how to let first box display "game system"? like as above ideal mod "MAME" text box?
This is something I haven't done before, probably the part of the theme that requires a bit of tricking. It would be easier to have the system box at full height, then the two rows of thumbnails.
Also, how to display game name in each box? Agree with one row is easy, but do you know how to make 2 rows?
Adding the name is not difficult, I made it in a test theme that is not published, it's a simple extension of the carrier.nut module where instead of just adding a snap artwork you add also texts or wheel artwork. Two rows like in my theme is quite easy too, although the theme will be a bit less fluid than the standard one line theme. The difficult part would be to implement an "irregular" grid like the one you showed in your mockup, but if it's predetermined I think it can be done too.
It's intriguing and I like the look of the theme, but I don't have time to code right now, otherwise I'd be glad to try it