I agree wholeheartedly with TakuaDE. The sounds used really do sound like someone's moaning and it's a great idea to wait for you to move until a level starts – it's annoying to be killed right after a level loads.

My complaint would be that I nearly quit the game because I couldn't figure out what to do – it took me a while to learn you have to hold & release a key. I've been trying to change colour to cyan and collect matching balls or hold a combination of buttons to create an opposite colour instead.
It's okay to not tell us everything – but the fun is in learning what to do in the game, not what the controls are. So as for instructions, I'd just update the instructions to something like "Arrow keys for movement / hold & release WASD to emit sound waves".

In the full game, boss battles sound cool, multiplayer might be fun, but if you aim to create hundreds of levels, make sure you add new kinds of enemies. That doesn't just mean new colours and new button to hold; you could invent more creative (and difficult) ways to dispatch an enemy. E.g. a red ball you can't kill by yourself, but you can lead the comet to kill it. Half-coloured ball which has to be turned white by holding a combination of buttons. Or you can make a level where you can't touch the walls, the walls have a different shape. Or obstacles, powerups etc. Whatever you think would fit in the game while adding something new every couple of levels.

Good luck. It was a pretty interesting and original game, albeit sometimes a bit frustrating.

This is an intersting game. I kinda liked it but I have some remarks.

First, the sounds made by the player (the ball) are so weird, they seem like moans or something and that might be a reason for me not to play it, at least not with sound on.
Second, the pale color of the balls, the first ones you encounter... I am colorblind and I found it extremely difficult to differentiate from, normal eatable balls.
Third, movement. I don't know if it is intended but after releasing the arrow key the ball keeps moving, like it slides a little bit further. This made the game a little bit frustrating for me, I would really recomend to make th eball stop when you release the key.
Fourth, levels. Some were fine and entertaining, but others were frustrating. There are some levels where you have a split second to activate your ability before you are killed. This is in no way fun and almost made me exit the game. You should be given at least some time to react, or make it start after you move.

The music was nice, the ambientation too. In general is a good game, but if it were to left like that I would not recomend it. The previous statments should be addressed before considering it finished. Adding some instruction would be a nice touch too, though I found it nice to figure it out on my own.