Yes, as you progress you can upgrade your characters further. At the beginning of level 7 is when you can finally max them out. You can also skip a lot of the cut-scenes with the B button which helps speed things up a bit. Screwed myself in one level by dying after getting a collectable and not realizing I had to pick it up again but all in all a relatively quick 1000 thanks to the guide here and on gamefaqs. Great job and thanks for all the work put into it.