Great except for a few things.
On level 1-2 I think it was, just after killing a giant ear of corn there was a toxic waste spill. I fell onto it and the robot shot off the top of the screen and then the camera sort of fell below the world and died. Other than that I was enjoying the game. Nice selection of weapons and a good variety of enemies. I liked the bosses. The art was all great. I would suggest making the robot move a little faster. I would also suggest changing it so that you can aim while in the air. Also, the shield is practically useless. You would have to anticipate the enemy attacks in order to have it out in time. And then its too slow to take the shiield down shoot once or twice and put it back up between attacks. The shop screen between levels was well done. Some sort of animation or notice that the robot was being damaged would have been good. Looking over at the small health percentage was annoying. Overall I enjoyed the game despite the few flaws.
Graphics: 9. I loved your style. There was a huge variety so you could tell you put a lot of work into them even if I only did get to level 1-2. I didn't give you a 10 because I didn't particularlly like the walk or jump cycles for the robot.
Style: 10. It was a unique twist on the platformer. Even if some of the collision detection was perfect, it was definitely worth my time.
Sound: 5. Unfortunatly I had my speakers turned off for other reasons so I can't accurately judge this category so I gave it a score in the middle.
Violence: 8. Not too much blood and gore from what I played but it was violent in its own way, and thats a good thing. I enjoyed the variety of enemies (especially the guillotine). I would have liked to have seen some sort of robot animation for when he was damaged though.
Humor: 10. Octopus/squid thing in the house. Giant ears of corn running around the yard. It was awesome.
Overall: 9. I really enjoyed the game. 5/5. 9/10. If you improve the gameplay to make it more fluid you could have one of the best games on NG.