Rather than going to the 360? The actual sequel is going to be on the 360 aka Overlord 2. This is another spinoff that's going to be pointless like the Soulcalibur one was. The actual main Overlord game isn't even good. I can't imagine what this game will be. There's little hope this or Overlord 2 will be any good.
Overlord 2 is a sequel
This is a prequel..... how is it hard to understand.
Do you class Resident Evil 0 as a spin off?
IMO a spin off has to either deviate a lot from a running storyline (ie a series of games has a story running through all of them, a spin off would be in the same world but with a different story) OR have different gameplay, ie Halo Wars is a spin off, or FF versus is a spin off.