"it is indistinguishable from shareware from a decade ago"
- that's just a little bit of an exaggeration isn't it?
You have to keep playing, the sheer variety and dynamism of the levels is very impressive. The integration of the level editor makes it even bigger, giving you thousands of levels to play.
The graphics aren't as nice as they could be but in terms of gameplay it's got to be the top of it's genre (apart from Breakquest maybe?). Anyway people love it - otherwise Reflexive wouldn't keep churning out new versions.
OF course not everyone will enjoy it. It is a "casual" game afterall