@CasuallyDressed - Thanks for the info.
I have £25 sitting on my 3DS at the moment, but am finding it real hard to pull the trigger on this one. I think I'll finish up what I'm playing currently (Warioland 3, Y's 1 & II, and To the Moon) before deciding. I don't have a CPP and something about that default control scheme tells me I'm going to hate it. There's also the fact that I recently went back to Geometry Wars: Galaxies for the first time in years and was really digging it. Although Nano Assault is quite clearly a very different game, somehow I don't think the comparison would be favourable.