As far as i can remember lots of collectibles and lots side missions in prototype i did like the game a bit like crackdown. I would recommend the game it is probably very cheap now
not a must have but it's good.
I got 950g in Deadspace 2 which tbh was not really that hard there is a glitch to help, with that last 50g hardcore is a bit of a pain.
Deadspace 2 an amazing game a must in your collection.
Personal choice Deadspace 2 no question better game easy to get 950g. Prototype if you can get it cheap it's a good game very underated i did not come close to maxing it out.
As far as difficulty is concerned casual on Deadspace is very easy.
Prototype on easy is also easy but all those side missions and collectibles are a pain.