People said that my laptop wont take bioshock but it did how?

Okay i have an dual core 2.1ghz porocessor and an ati mobility radeon 4530 hd people said that i will run bioshock with no lag on low-meduim settings Well..i bought the game the other day and i installed it and it ran perfectly on high settings i got no lag at all will i run crysis warhead????cause i ran bioshock plus io tested on can u run it ty