This one is pretty good. I enjoyed it.
Well, hearing the title Gamerboy I thought about a human boy but that doesn't really matter.
Also I already see that you got inspired by a bunch of other games but it's not a bad thing.
Pros:
+ Music is nice
+ I liked this little fall animation and somehow how boss is drawn animated
Cons etc:
- You should balance audio volume. First time I've played it I had to lower it myself after the narration and again after starting the game.
- You don't use all of the arrow keys as the poster implies
- Medal doesn't work
- What's the point of GB?
- You can fall through platforms at random during boss fight
- When I defeated the boss all I got was a white screen.