pro
Q-Games laid the foundation for this undertaking when they first developed the built-in PSN music visualizer called Gaia. It allowed you to view the earth from space with the help of NASA's satellite images, the Blue Marble Project, while listening to your favorite tunes. I imagine 4am is doing quite the opposite, taking you down into the micro cosmos of living organisms, visualizing the beats as individual amoebas and rhizopods, stretching, swirling, twisting and transforming in a forever changing organic primordial soup. 4am essentially empowers you to be a DJ of this audio/visual synaesthesia and broadcast the result live on PSN. The game requires you to use 1 or 2 Move controllers to manipulate the beats within the so called Virtual Audio Canvas, and you do it with ease as soon as you learn the colors of the palette. PixelJunk 4am's mechanics suits Baiyon's style of music like a glove and it's all about slowly layering beats, bending notes and evolving the track as you please. It's physically impossible to stand still once you get started and the genius interactivity of dragging beats and modifying notes will most likely transcend into a mad danceathon.
pro
Those of you that became a fan of Baiyon's audio/visual work on PixelJunk Eden will be happy to see him return and put his unique brand of aesthetics on PixelJunk 4am as well. The musical style of Baiyon (or Tomohisa Kuramitsu, his real name) is often ambient and mellow but sometimes borders on glitch and lo-fi even to the point of being abstract, but has it's roots in electronica, techno and house. It is often recognized by pulsating bass or drum beats highlighted by various intangible melodic riffs resulting in a hypnotic concoction of sounds.
pro
This might be the closest a video game has gotten to a DJ-like experience and you feel the symbiotic relationship with the crowd listening in on your performance, giving virtual "likes" in the form of "kudos" appearing on the screen.
pro
The best use of the PlayStation Move controller to date, using vibration and 360 degrees of the spacial environment to fill your audio artwork. PixelJunk 4am encourages you to experiment in perfect sync with the beats and it will leave you mesmerized.
con
2 local players can do Co-Op and create tracks using Move controllers simultaneously but unfortunately there is no online Co-Op at this time.
con
The PixelJunk 4am Viewer is free for everyone that wants to listen in on the music and while you can promote your sessions via Facebook or Twitter (#PJ4amLIVE) I wish you could broadcast your performance through a web interface for your friends too.
con
As much as I adore Q-Games vision of 4am I realize it might be too niche market and abstract for the mainstream gamer and I hope DLC packages with guest artists would broaden the appeal.