I had fun with this one, I think you did a fairly good job translating a twin-stick shooter for gameboy controls. The fact that you fully stop in place when you shoot feels pretty clunky though. Maybe if you want to keep that type of mechanic it'd feel better to only slow the player down for a bit instead? It would keep that risk there but wouldn't fully take away the player's control.
Also, and maybe this was me misunderstanding a mechanic, at some point my shots just stopped doing damage (Or maybe were just doing very little). I was using the shotgun, and a single one of the ghosts tanked about 20+ fairly close range shots before killing me lol.