I have to admire the ambition at doing a a collection of mini games for a game jam, since I tried it myself last Ludum Dare. The lesson I learned from that was... never again : P
Seems like you had the same problems we had then, the art style felt a bit uneven and unpolished, both on each individual game and when you think of it as a whole troughout the collection.
I really feel that the block game could have been much more interesting on it's own, with more thought out puzzles, perhaps a slightly different art style and more audio. I was missing audio as a whole? Everything felt very empty, and I feel that som ambient sounds and music would have helped to tie everything together better.
Especially having a unison sound style troughout several different games would have really tied them all together a bit better.
But it was still pretty nice for a game jam! Have seen (and made!) worse! Good luck on future projects.