The input lag is horrible; I have no problem with bullet hell games, but there's sometimes a 0.5 second delay between moving my mouse and the crosshairs responding, or even 1.0 second between keypress and movement.
Good visceral thrills. Molotov cocktails are useless -- the point they land is above the viewable area when thrown, so you cannot know what they will hit.
Stolen art, stolen music, and the interface isn't even in the language of this portal site -- hell, doesn't even match the language of the loading bar nor distributor's logo.
The flash player is too tall for my browser (1024x768), and each time I scroll the window up-down to see the whole play area, the game pauses. I find this very annoying.
Don't buy the jumpstart upgrade -- you'll fly right past one of the gems you need to pick up for "completing" a level, and I'm unable to un-equip a jumpstart upgrade. I have to waste precious time trying to fall back down to get the gem I missed.
Touch a wooden crate, fly backwards so high and fast that I pass beyond the start of the level. Weird. There were also some times when if I pressed left & right too rapidly, the car would swim straight up into the air.
If I 'cast' a spell too quickly after the last one, the runes will light up in the correct pattern, but no spell is cast. This is frustrating. I do like the drawing interface though (were you thinking of touch-screens?).
 "Trap: Volume One"){kind=icon}
 "Amorphic Blob"){kind=icon}
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 "Earn to Die 2012"){kind=icon}
 "Zombogrinder 2"){kind=icon}
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 "Terra God"){kind=icon}
 "Randobot"){kind=icon}
 "Cargo Shipment: Chicago"){kind=icon}
 "Angry Animals 2"){kind=icon}
 "Penguins Can Fly! 2"){kind=icon}
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 "WarMagic"){kind=icon}