Space Invader5 - Known bugs or required improvements
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* Gameplay is still a little slow and tends to get slower as the game goes on and with
subsequent games.  This is due to some memory leaks that I'm still tracking down...
* Aliens occasionally scroll off the edge of the screen when a left or righthand-most
alien is killed that's not at the bottom of its column
* Missiles and aliens bombs can occasionally go slightly off course when the aliens are
left-most or right-most of the screen
* Game can ocassionally crash if it's the foreground app and the machine is switched off
for a long period (say >2 hrs)