http://h1.ripway.com/calchaven/TankInvasion2.zip <---

Controls are as follows:

Arrows: Move
A: Locks direction.  While A is held, the tank will not change direction.
S: Jump.  Hold the button to jump higher.
S, in the air: Hold to hover, therefore slowing your fall.
Shoot

THere's one level in this demo, and it's quite entertaining.  Enjoy!

Questions/comments are welcome.  And I left in a bonus glitch at the end, too!