Daxter, it happens because the computers find it difficult to notice when three or more keys are pressed simultaneously. It has nothing to do with the coding of the game.
Amid the huge torrent of thoughts about this game, I feel this could all be summed up with "Why?".
But I mean, seriously... made in one day? What was that, 20-odd minutes tops? I would, however, recommend this for newgrounds... maybe?
The most important question here is not "What compels a businessman to attacking a stream of turtles?", "Why ARE they a stream of turtles?", "Why is he being paid to bounce turtles around like so?", but "Why can't he swing his hammer a second time?" XD
Good game! Just a few things annoyed me about it: no idea how much I've progressed in each achievement; the speed up button doesn't appear to do anything (that might just be me); the upgraded cannons only seem to speed up and the game continually seems to believe I'm double-clicking. That last one drags the building parts out much longer than i'd like.
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