Dyad is: free for PS3+ users, also incredibly wonderful.

[Special World]

I recently tried out Dyad expecting it to be some sort of style-over-substance pseudo-art game, sort of like Rez, where you're playing the game for the visuals and audio but not the mechanics. Imagine my surprise when it turned out to be one of the gamier games I've ever played, a sort of reimagined Tempest-like tunnel shooter, with a ton of different levels and challenges to master. The game starts out really simply and just keeps building on itself, until it becomes this crazy psychedelic audiovisual thing that barely even resembles a game to somebody walking by.

But it plays like a game, and it's damned good. I definitely encourage anybody with PS+ to give it a shot, as it's definitely worth its original asking price. And hey, maybe it'll get you in the zone for Jeff Minter's upcoming TxK.

[PC Engine Fan X!]

I did d/l the Dyad demo and have yet to give it a spin. Like the cool stylized fonts that make up the Dyad moniker.

PC Engine Fan X! ^_~

[antares]

I agree it's a very good and addictive game, everyone with a PS3 should try it but it's not a shmup. Though it looks similar to Tempest the gameplay is very different, more like a rhythm/music game.

[Special World]

I would personally say it's a lot like Tempest, at least as much as you can be like it without completely aping it, and the musical aspect of the game is just an added appeal layered over the gameplay. You could remove the sound entirely and you'd still have very much same game and gameplay, it just wouldn't be as appealing from an experiential point of view. It's a lot closer to Tempest than it is, say, Amplitude. And they were very obviously inspired by Jeff Minter's Space Giraffe, though potentially a number of games from other genres as well.