Thank you so much for your comment Teddemeister! :)
Well, is not strictly a game boy game, but it shares some limitations of the actual game boy (like resolution and palette). In fact, it would be very hard (and possibly impossible to export it to the game boy (that parallax effect))).
You could use any engine or library to make a game that looks like a game boy game. But if you want your game to run on an original game boys, you should learn assembly.
Hope it helped!