Okay maybe not 5-6 lolol I just realized thats a bit of a high number.
At the very least 4, then you would still have the rival thing. Like you unlock the character, Tomba for example and then you play his story mode, find out who his rival is and you're like "OMG No way I have to unlock him!? How? HOOOWWWW!?!?". Lol.
That wouldve been cool. You barely get that surprise anymore because of the internet, and the last game i saw it in was Kid Icarus Uprising, but that was the first to do it in a while.