Notes

Coordinates:

X direction is positive in the right direction
Y direction is positive in the upwards (top of screen) direction.

Timing:
Use the game cycles for timing (60 cycles/second). gameTime contains two things: the real time passed in the game, and the "game time" passed (uses time that the game is the active window). Both of these, however, are vulnerable to getting out of synch with events that are dependent on the game cycles. Thus, use game cycles for timing. If the game chugs, everything chugs together, so it gets slow, but it stays together.