It's fun, but underground there's a few places that seem guess-and-check. Considering you only get 3 lives, that's not a good idea IMO.
EDIT: There are a lot of things that I don't get either. You might want to tell people in-game what everything does. I got to the part with the monster that shoots balls, jumped up on the battery because I thought it might do something, and I got stuck. I had to commit Self Delete, losing my last life, so I got a Game Over. Not cool. :c
The Update button breaks the game, too.