I manage to borrow my uncle's PS3 for a month since he is not using it at the moment, along with Uncharted, heavenly sword, MGS4, DW6, Winning eleven and Lair. Any PSN games that I can consider? My uncle got a HK$200 card for me to buy games with but I am not sure what to get.

pixeljunk monsters and super stardust hd are amazing, they gave me more fun then some full priced games

I've probably played Super Stardust HD more then the full priced games I've got. All of them. 10-15 minutes here and there is too little for the large games but for SSHD, it's perfect. also, SSHD has trophies (aparently they are good...not sure yet why).

I'll third Super Stardust. It plays like an easier and more fair version of Geometry Wars. (Can change weapons, see where enemies are shortly before they appear.) If you've got another controller you might consider getting a the multi-player pack for an extra $5. The Vs. mode you get with that is a lot of fun as well. You can also get a free demo of Super Rub-a-dub if you want to try it.

Pixeljunk Monsters is a great game and it's on sale this week for $4.99!! The regular price is $10 I think.

for some psn games like PJMonsters, SSHD, .. there are demos, you should try those first and decide then what to buy

Super Stardust, Pixeljunk Monsters

when is ratchet quest for booty coming out on PSn? what about ragdul kung fu?

SSHD and PJ:M I'll also backup. Both great games with great value. I've also found that I really enjoy Everyday Shooter, and flOw(my first PSN purchase :) ).

If you're into puzzle solving type games, I'd say give Elefunk a try also. It's lemmings-esque but quite entertaining. Also if you have a female in the house she'll be entertained by the cute elephants (and yell at you when you let them fall hehe).

Stardust hd, tekken dr online.