I found that if you move the mouse offscreen while playing it will lag for about 3 seconds but in that time you can still get shot to hell this needs to be fixed
Try shooting with Shift instead. Might work better. Unfortunately some keyboards wont register left and space att the same time. Not a lot we can do about it :/
 "Time Clickers"){kind=icon}
 "The Most Wanted Bandito 2"){kind=icon}
 "Fear Less!"){kind=icon}
 "Swindler 2"){kind=icon}
 "Mega Mash"){kind=icon}
 "Pimp My Tree"){kind=icon}
 "Bullet Audyssey"){kind=icon}
 "Firebug"){kind=icon}
 "Pixelvania Racing"){kind=tracking}
 "You are a... The Sequel"){kind=icon}
 "Pixle Physics"){kind=icon}
 "Pumpkin Master"){kind=icon}
 "Concerned Joe"){kind=icon}
 "BeGone: Guerra"){kind=icon}
 "Accelerator"){kind=icon}
 "Little Cave Hero"){kind=icon}
There are times when you can get a better score by using the double jump. You don't need it to complete any levels, though.