I've programmed a game named Battle in Casio Basic. It's made on my fx9860GII but it will work also on PRIZM.
There are two spaceships, you are one of them and you must destroy the other. At the begin you can choose the shield power of the ships.

Controls:
Arrows : Move
[EXE] : Missile
[(-)] : Laser
At top of screen you can see your shield power and the shield power of the enemy.
At the Left side you can see the power of the Laser, if the bar is full, the laser is ready to fire.
Screenshots:





Download:
http://naib864.bplaced.net/Battle/Battle.zip