:
|
I've 100%ed #3, and got damn close with 1 and 2. I can't think of any skill points you couldn't get in your first playthrough, even if some of them aren't really feasible until challenge mode. The only skill points that you might be quicker in many Challenge Mode playthroughs would be ones that involve buying things, because the arena rewards reset in each new game.
|
The first few games weren't too hard to 100% but I clearly remember at least one of the latter installments where it is impossible to get every skill point on the first playthrough.