A lot of content in this game! It's impressive to see. I think it's a bit of a double edged sword when the map is huge though because when there's not much in between to explore or interesting to see, it can feel a bit boring when you're walking around. It's a common complaint even in huge-budget games. I think it would have been a better experience if you had condensed the map more.
The music is fun, but I think the game lacks sound effects for common actions such as walking or jumping, which also contributed to the aforementioned problem, especially when the whole game involves tons of walking.
The graphics are quite nice, even if they're simple.