Ok, so there might be one too many versions of Echochrome (PSP, PSN) running around, but they all still operate under the same rules. If you're wondering whether you should buy Echochrome, you may want to watch these new gameplay videos.
Remember that Echochrome operates under five rules which basically say that "what you see is what you walk on." The first video demonstrates how these rules apply to platforms, the second video shows how they apply to holes, and the last one to blocking.
If you find that you're still on the fence on this game (perhaps you just need to rotate your world a bit), then you might want to pick up the demo on PSN. It's free too. You can check out more info on the different Echochrome versions by following this link.