Fun - but physics and Insane? *shotgun --> mouth*
This game can be a lot of fun. Were I just the casual/non-achievement hunting player, I would give this a fun play through on normal and call it a day.
However, the game mechanics make achievement hunting annoying...
Of course the mini-games, like Pool, Air Hockey, and Pinball are absolutely ridiculous - imagine trying to play these games in a world where physics didn't follow the rules.
Then you get onto Insane difficulty - a beast by itself, but then you get these extremely long load times after each death. Then there's the stupid turret fight, which is ungodly frustrating. No dodging, no hiding and relentless waves of pain!
Fun game though. If you're happy with 800 or so points, give the game a go. But prepare for frustration if you want the whole quesodilla.