Graphics: I like them mostly. Dated? Well, sure, but that's okay.
Music: I did say that it was okay that the graphics were dated, but the ragtime-style soundtrack to this game is annoying, so I turned it off. Sound effects are loud and unfamiliar but I guess I'll get used to them.
Game Design: There is too much new stuff to process, but I played around in the editor in trying to port CC1 levels to compare...from what I can tell there is both more and less flexibility with the rules in CC2. Levels that were pedantic-compliant on TW seem to generally be able to work in CC2, but otherwise I'm not sure. Once we get used to working in CC2's rules I think the richness of the palette will be a boon to developers and we'll have no trouble finding people who want to make a CCLP for CC2. I can't wait to see what kinds of tricks that our community could come up with. I predict the green pop-up walls will be added to the list of "hated misused features" alongside invisible walls.
Level Design: I haven't played beyond level 20 yet. The early levels are kind of tricky! I really dislike the number of turtle/pop-up variant levels so far. They seem to be introducing new components very slowly, so i figure the "Lesson" levels will continue well into the game with more advanced and difficult components. None of the levels so far have impressed me a lot, but that's fine. I'm sure there are some more of "my" kind of puzzles ahead.
Editor: Frankly it stinks. It crashed the game multiple times (causing me to lose a lot of data...be sure you save before you test a level) and is a pain to use. Someone is going to create a workalike alternative if the problems aren't fixed (it sounds like the devs are going to improve it though, by adding magnification and hopefully patching the crashing bugs).
Multiplayer: This is a thing I didn't expect to see. I don't think I'll ever use it, but that raises some possibilities.
Other: The lack of a Linux version makes me sad, but I can live with it for now. The dev team hasn't mooted the idea of ports, but it is probably not going to be forthcoming.