Everything about this game was amazing to play. It all feels like it could have been a real gameboy game. The only thing I found weird is that the enemies keep flashing and I thought my game was bugged because I couldn't climb ladders at the start.
the flashing looks more like semi transparency on hardware devices and some emulator. The frame rate is just off a little in the browser emulator. Since you cannot do semi transparent on gameboy the quick flashing is a way to achieve it.