I thought it was really cool and I loved the cutscenes I thought they made it fresh. Btw, what's the other 18% or so for? How are you supposed to make it 100%?
100% is getting all the orange (yellow?) boxes in every level and going through every door (basically just exploring everywhere). You can tell what you have left on the map: a crown means you've completely cleared the lvl, a flag just means you beat it but left something behind. You can go back to any level with any character in your team to try to find the rest.