1: get linger in shadows its a pretty good demo art type of thing comes with triphies also, has ace soundtrack and you can get some super screen grabs to use as wallpaper.

2: quest for booty is good but id get the disc version although you still have to install 4gig.

3: flower is a must its totally amazing gaming experiance

4: stardust never played it i dont like 2 stick shooters.

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flow is a good game akin to flower, but you must get pain. for the price it looks and feels like a full price game you can also download add on packs which will increase longplay.....but pain is being released at retail along with all addons so u may aswell want to keep an eye on that.

if your gonna get warhawk id just get the retail version same as quest for booty. to much space on HD.

1) The last guy (very fun and funny game trophies coming soon)

2) Pixel Junk Monsters and encore (tower defense with custome soundtrack and trophies)

3) Savage Moon (3D graphics make this an excellent choice for a good strategy game)

4) Ragdoll fists of plastic (best all around local 4 player fighting game on psn)

5) Everyday Shooter (if you like geometric shooters with vertiex graphics, there is not better)

6) Astro Tripper (fantastic, nostalgic, old school shooter)

7) WarHawk (3rd person shooter with up to 32 players)

coming soon to Psn.

1) Fat Princess (32 player, class based shooter, and is like capture the flag with cake!)

2)Trine (customizable levels, great graphics, and awesome platforming)

Must haves:

Fat Princess coming out soon [Last I heard, coming out in June] looks really fun and reviewers are kind of praising it.
Bionic Commando
PixelJunk Shooters [From the trailer, looks really fun]


Warhawk is good, but you can get a disc version instead for same price.

Wipeout HD is fantastic, honestly....a must buy. Id give it 9/10
Burn Zombie burn is also very very fun, although its low production values show off. I say 8/10

Btw, Flower is 11/10

Pixel junk eden and BURNOUT PARADISE.. two must haves..

GET PAIN!

Noby Noby Boy

Your list is good. I'd say Siren and Tekken5 but they're over your limit.