Very fun game. I'm glad you didn't make the 'normal' too tough. Playing it on 'hard' mode after beating the first go round has been difficult for sure.
The level of difficulty is good. The graphics are nice.
It's fun that instead of an upgrade that you are 'debugging' your robot.
The opening and closing sequences are cool...it tells a bit of a story but we are left with a bit of a mystery.
Overall a very good game (albeit a bit short) that I will soon beat on Hard Mode (hopefully) but I wanted to go ahead and write the review.
Best of luck.