Hi Itizso, I've been following your RetroFab projects for years. You're doing amazing work for games preservation!
I absolutely think it's ideal to play these old handheld games in a handheld format. So a downloadable, offline mobile player would be huge! It would be such a great way to pass the time on the go :)
Bonus points if the games are also playable in portrait mode, especially for the Dual Screen games, but I think having the games playable offline is a more important feature first.