Asriel on 20 June 2009
I found Prime 2 the most difficult, when I replayed them early last year.
My first playthrough of Prime 1 was difficult, actually, but Prime 3 wasn't particularly tough.
I did all three 100% in one week and thoroughly enjoyed it, and like I said, 2 was most difficult. I'm sure if you stick with 3 you'll be ok. Just make sure you look for health and missile expansions.
