My planned entry wound up not meeting the conditions but I wanted to share it anyway: Many Mini Ninja
My concept was to use the mobile game Ballz as the template for a quirky RPG. Unfortunately a nasty cold kept me from working on it as much as I had hoped and it's not much more than a clone right now. Maybe it will inspire someone to create something more RPG like.
It's an interesting idea that could be a lot of fun with some more work. One thing I did notice was some odd collision handling. Sometimes I could push against a wall and when I released the key the player would start moving the opposite direction even through I wasn't pushing anything. It seems to range from just a small drift to a large bounce back.
I honestly haven't done enough testing on this part of it but the two approaches are to spam click in order to try to survive longer or let the fish build up to try to match a larger group which gets you more points. I'm not sure which is the better tactic but I usually go for bigger groups in the beginning when the new fish arrive more slowly and then rapid click once it gets too fast.
I haven't played many of the entries but this will be tough to top. The way new concepts get introduced is amazingly well done. My only issue is that I want more of it.
On my first playthrough I only found the second secret. After finishing I immediately started again to try to find the other two. I still can't find the third.
This was a fun puzzler. I'm glad you included a skip feature since I did get stuck on a few levels but I at least got a chance to see/try them all. I think having a level screen that lets you see which ones you've completed would give people incentive to try to complete a level rather than just skipping through.
With a bit more polish this could got from its current "pretty fun" to "I need to keep playing this". Apart from some more instructions on the combos as other have mentioned, some hooks to make the player want to play again would make a good addition. A high score (longer the combo the bigger the score), longest combo, highest wave, etc.