Unless plans changed Todd said horror. And really,it's the only genre that would fit with the budget they're looking at. And Spawn is basically horror at its core just with a super hero slant.
I think of stuff like the first half of jeepers creepers before it showed the monster. The amount of suspense and horror that can be derived from playing spawn in the shadows and never quite knowing what you're seeing is great.
Wether they can pull it off or not is up in the air,but small budgets can be a positive as if you have a good director willing to be creative some cool shyt can be pulled off rather than just throwing money and cgi at something.
Considering how good upgrade looks as an action film and with his horror roots,Leigh Whannel could pull this off. We shall see if Todd has what it takes to do this.