Really solid entry! Absolutely nailed the game boy aesthetic (it is a game boy rom, so that checks out). Loved the references to games past - the EarthBound Beginnings one was nice. Soundtrack is kickin', graphics are great (love the isometric view), the writing is on point, and the length of the game is perfect for a game jam game with just enough reason for replaying with the timer and rank.
The only suggestions I could give are about collision and inputs. Sometimes these things felt clunky enough to be distracting, but it was ultimately fitting for a game boy game.