So i grabbed Hitman 2 for 2€ on GMG

http://www.youtube.com/watch?v=Gx2m6OAlj8w

was it steam redeemable?

I think that GMG version is significantly harder. You should have bought it on Steam

Hitman games are oldschool, hardcore games. Generally 1 mistake = repeating whole mission if you want do it right (not Rambo mode). If you like easier (but still challenging) sneking games I recommend splinter cell series or new Deus Ex HR.

Or wait for Hitman Absolution this year. It will feature health regeneration, checkpoint system and instinct mode (where you can see your enemies through walls and such) so i'm sure you'll definitely enjoy that kind of game mechanics