Awesome, I just tested it out!
So, to start with, the sound, music and visual effects overhaul is great. Everything now makes distinctive sound and visual effect, such as healing zooid's skill, speed pickup effect etc. That's a nice touch. As for the aquarium mode itself, it has a lot of potential both in testing out different zooid patterns and creating player's own level.
I've noticed a few very minor bugs so far. First, whenever I finish the level and push the DIVE button with my mouse to get to the next one, it always triggers whatever skill I have assigned for left mouse button. I expect mouse button not to trigger assigned skill when I push the DIVE button (or any interface buttons). Similar things also happen when I use aquarium redactor interface and place things with my mouse - after I exit redactor mode it triggers my skills for all the buttons I pressed.
Another, really minor bug: I pick a thing in aquarium redactor and start placing it, but during rotation, while my left mouse button is down, I decide to cancel the placement and push right mouse button. Object placement is cancelled, but when I later pick another object in redactor menu, it is instantly placed on the level at the position I previously cancelled. I do not expect objects to be placed automatically in previously cancelled positions.
That's all I could catch for now since I didn't have much time.
As for recommendations: It would be nice to have background selection for aquarium level, so that if I decide to make my aquarium walls and decorations from "fleshy alien" things, I could pick a background that fits this theme. Or maybe there is such option and I missed it?
Another thing is that aquarium redactor interface isn't that self-explanatory as I wish it was. I spent 5 minutes trying to figure it out before I realized how to rotate objects (you do it by dragging the mouse while pressing left mouse button when you place the object). This interface still needs some love and polish :D
Finally, I have a rather tricky suggestion. Let's say I make a level in aquarium mode and I want to share it with community so that anyone could play that level. Will there ever be aquarium level manager that would allow players to browse their created aquarium levels and share them with each other, similar to how content was shared in Spore? I assume my aquarium is stored in a file somewhere in game directories, but I don't really know where and there's no in-game aquarium level manager yet. I know it would be really hard to make so I don't expect any clear answers on that, nor do we really need such manager right now since aquarium isn't developed yet for players to actually make levels worth sharing.