Man you must have played non stop to beat it in two days. It takes a good 20-25 hours the first time through, unless you level up really fast, and there is an option to do that. With all the other options the game can easily take 45-50 hours. And it most deffinetely is a great game worthy to be purchased. But if no other games appeal to you (and they should), than a PS2 aint worth it.
Other games I'd recommend: DMC, Timesplitters2, MGS2, FFX, GTA: VC, Tekken Tag, VF4, and others that I'm to lazy to list right now.