Great game
This is a perfect example of a simple yet addictive flash game. The only two complaints I have which stop this game from being 10/10 is that there is no breathing room between starting the level and enemies spawning. This resulted in a cheap death when a helicopter spawned in front of me at the very beginning of the level giving me no time to react or avoid it.
Also though this may be either done on purpose or as a sacrifice made on part of the aesthetics since the clouds and enemies are the same colour it's very easy for some enemies to get lost during some particularly cloudy areas making it extremely difficult to spot and avoid them. Other than that it is a stellar game.