(click here to pause)
First some ranting...
The Pause-button is a sadistic joke. You have to click a field that appears to offer you to pause the game and totally unexpected: you have to navigate a sub-menu while the game continues merciless. To make matters worse I had to look for it once I needed it. I would have expected space or the P-key would have done the trick...
The grey "-"-ball isn't mentioned in the instructions. My guess was he would be bad, so I blocked it. What does it do, exactly?
The darkened screens when a new level begins, as well as explosions block your vision while the game continues and add some new challenges by that. I'm not sure if it is intended that way. A short pause of a second while these things happen would seem appropriate.
Until now I have no idea in what manner the laser is charged. I fired it 2 times during my first run after it reached "devastating" and got a beam for 2 or 3 seconds. When I reached the final level in my second run I had to fire it again and the result was a very thin line that lasted only for the blink of an eye - despite the fact it was still "Devastating". I would really appreciate it if the instructions told how this damned thing works. In addition it could use a hotkey.
Also, there seems to be a glitch that lets a white "+"-balls disappear when they reach the middle of the right side. It happens 3 times or more each minute and is pretty perplexing.
M-key for mute would be nice, too.
I managed to get all medals by completing all levels twice and committed suicide. This took quite a while and when I finally wanted to submit my score the button did exactly nothing. I've encountered this problem various times before and it is quite common: I would have to whitelist some unknown third-party domain. Maybe I want to do so, maybe I won't - but it would be really nice to know about which domain to whitelist beforehand.
Although there can be done much to improve your game it is a nice timekiller and I had a good time playing it, once I got the hang out of it.
Oh, and for the medal-hunters: The highest number of lifes you can have is 25 and the highest rank is 10.