Played Assassins Creed from begining to end with the spec in my sig.
It never crashed, the controls are fine, only time i had an issue was when you where too close to two buildings (in an alley way) and the camera jumped about a bit...But that was a camera issue, not control.
Internet issue? Come again? My nets on 24/7, only time i turn my net off, along with my A/V was when i played Crysis, to free up a couple of resources...Works fine with the net enabled when its patched up. Might have been your Anti-Virus or firewall.
As I said at the start, it runs fine, flawlessly infact, I had no slow downs at all, with everything cranked up.
What do you mean by unfinished? It's not buggy, other than a few rag doll effects I noticed.
great game to be hoenst, apart from it did have some repetitive moments

That and I wish they kept it in the early years, rather than having some plonka going back in time via his DNA