Currently Online 
Most of the game is pretty easy.
I'd say there are like 3 or 4 levels in particular that offer a pretty decent challenge.
I'm kind of mixed on the PlayStation themed levels. On the one hand, they make up 3 of my favorite levels in the game, on the other, I think AstroBot Rescue Mission was a better game without relying on any kind of PlayStation references.
I think my two biggest complaints about the game:
- The villain isn't particularly notable. A lot of other platformers have notable villains like Bowser, Dr Cortex in Crash, etc. Astro Bot doesn't have a villain.
- There's not a lot of theming. There's very little differentiating the nebulas. You could easily swap most of the levels around and it wouldn't particularly change the game. Having an water nebula where most of the maps have something to do with water would be more interesting I think. A ghost nebula with a variety of ghost themed levels.
