I hate it when games have extra content exclusively on some other site, but do not clearly point this out before you have already played for too long to restart on that other site. The game itself was entertaining, but is it really all that difficult to point out it has site exclusive content _before_ it is too late? Hence 5/5 becomes 3/5.
It has potential, but also major flaws. The lvl 16 is buggy (most of the time I "run out of time" as I start the level and the count down shows 5s) and there is no incentive to play the more difficult levels instead of grinding the early ones. In fact, you earn more by grinding the early ones because you get bigger time bonus! Also, the steering is rather way too sensitive, as slayerer already mentioned.
 "Slush Invaders Game"){kind=icon}
 "Monster Castle Defense"){kind=icon}
 "Bustabrain"){kind=icon}
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