It's really cool! I didn't like the default layout of controls on keyboard at all - I ended up flipping my keyboard upside-down in order to play. Obviously it would have been a lot easier to control on a real gameboy, haha.
Balancing a pinball table in a week sounds so difficult. I'm a relative novice at both pinball and pinball video games myself, so this might be mostly a skill issue, but I found it very difficult to shoot with intention on this table. Cradling the ball seemed to only put it in useless places and I had so much trouble shooting up the ramps. I was able to unlock the boss fight but died early without being able to hit the ball each time I entered.
Anyways the graphics are great, the song is good.. it's very memorable! Such a cute game. My high score was 119k... I might have to go back for more though.