I'd like more diversity in/and more Toy Box Game Discs. More ideas past tower defense and dungeon crawler types, and initial options to intermingle the various characters before completing the campaign.
Anything from platformers to survival/brawls to racing games. Even board game type options. Just more. I really felt that invigorated the Toy Box for those moments that you just didn't want to build anything, and needed something lighter and more arcadey past the playsets.