Isn't there 36 stars total? 9 per 'character'; i.e. 3 stages per character. I think I'm on about 22.
I'm just trying Skull (4-2) for the first time., it's going great! My skills have improved vastly since the beginning, the last couple of stages have been so fun - Monolith was particularly awesome, I was really pleased with the runaway mine train I crafted to beat the objective! Will post up some pics when I get a chance.
I'd started out with the goal of hitting silver and coming back for golds at the end, but I've managed a few golds almost accidentally in the last few stages
Love this mode. Initially I dismissed it, but it's been super fun. I really hope we get more maps / a scenario editor soon.
And for the billionth time, 'Career' mode should've been titled 'Scenario' mode; 'Challenge' should've been 'Career'.