What I'm wondering is that whether the developers of the both game are the same? Also, Bloxorz has 30-something levels, whereas cuboid has 60?

I'm absolutely not paying 10 bucks for a game I can play online for free. But if it drops half, I can let that go and buy it just for the pretty graphics.

I guess that kind of answers your question. Bloxorz pure puzzle, cuboid pure puzzle plus much cooler visuals.