The power(wattage) of the psu has no bearing on this discussion - the amount of power the computer uses + the wasted power the psu uses in normal operation(efficiency) will determine how well a UPS will operated any computer.
p.s. give us more computer info
Intel Core i7 3770 @ 3.40GHz Ivy Bridge 22nm Technology
NVIDIA GeForce GTX 660 2 GB
8.00 GB Dual-Channel DDR3 @ 675MHz
ASUSTeK COMPUTER INC. P8Z77-M PRO (LGA1155)
I also play a lot of video games, and most of them are really demanding when it comes to specs. Will this UPS work for me?