i really enjoyed the demo, light and fluffy and fun. i will have the full game in 2 days dependant on delivery, so i shall post my impression as soon as i have it.
All things considered, it's a fun game. Lots to shoot and many creative ways to off you foes.
I've faced one real boss and that was about a pain, but not hard at all.
My advice would be to rent it, as it does seem to be a fairly sort game. And for the love of God, if you have kids keep them away from this. Profanity laced and violent as can be.