I recently purchased some games from psn and I must say I'm impressed at how good they are for 5 euro games. Quite addictive and with fairly good graphics, these games are great if you want to burn some time but don't feel like taking something like oblivion out of the box. Cheap, instant fun and gratification.
Lemmings - Probably the most demanding of the 4, since you actually have to think a little on some of its 40 something levels. Probably the best value too. At 5 euros you just can't beat how great of a deal this is. Still, it's not quite as pick up and play friendly as the other 3. Also, you can't help but feel this franchise was originally designed to play with a mouse, and while I don't know if you can actually do that with a usb mouse, it's not like everyone has one available out of the box. It's still quite good, though, and a great time waster.
Blast Factor - This was originally sony's answer to geometry wars on xbla. It's much better looking though. As for playing better or worse, I guess it comes down to personal preference, since it's the same at the core. I personally like geometry wars better. It's much more challenging and the fact thet you're confined to a single rectangle with stuff constantly popping up on screen makes it a must for the hardwired reflex maniac. Not that I'm one, mind.. I digress though. Blast Factor's good entertainment, but unfortunately it's been surpassed even in its psn home by better offers like Super Stardust HD. Still a good game at 5 euros.
Flow - This one was originally a flash pc game, but sony saw potential and comissioned an exclusive ps3 version. This game is great. The premise is simple. You're an aquatic creature. You eat other creatures and evolve and become bigger. Its simplicity is what's great about flow. It's seemingly not very complex, yet very entertaining and relaxing. Sixaxis control is also very well implemented. Maybe the best use of the sixaxis' tilting abilities I've ever seen. Visually, it's very stylised and looks great. A great purchase. Something truly original and worthwhile.
Super Stardust HD - I'm hooked. This game has me by the balls and won't let go. Everytime I'm not home I want to be playing this. It's a bit more expensive at 7,99 euros, but boy is that money well spent.. You're basically controlling a ship orbiting around planets. Giant asteroids come. You have to destroy them. This seems simple, but the way it's executed is what makes this a kick ass game. Basically everytime you break an asteroid it will break into smaller parts and then instead of dealing with one potential threat, you have nine.
It's so chaotic and overwhelming at times.. a real test to one's skill and reflexes. You have to not die in order to raise the multiplier and make millions of points, and that's the real challenge. Sometimes you can have like 30 asteroid pieces hovering over the planet and 15 enemies chasing you at the same time, so some concentration is needed in order to escape and not lose a precious life. Fortunately you have an arsenal of 3 powerful and highly upgradeable weapons, each of them more suited to one specific type of asteroid.
Oh, as a bonus you also get highly detailed asteroid and enemy models, great explosions and generally superb presentation. This one is a must. Really. And yes, it's better than geometry wars. And much more addictive. You must get it now.