The goal here is to add power-ups to make Factoroids more interesting.

For "stealth", make the ship semi-invisible and able to pass through asteroids without triggering a collision.

For "shields", make the ship behave like an indestructible battering ram, destroying any rocks it runs into.

The power-ups should be saved when the player earns them.  Designate keys that will activate these power-ups if available.  When activated, the power-ups should function for a limited period of time (perhaps 10 seconds).  Do some gameplay testing to find a duration which provides a good benefit without making it trivial for the player to clear an entire level.

The power-ups could be earned in a couple of ways:

1. A player could automatically earn one when a level is completed.

2. Rocks could occasionally become "bonus rocks" for a second or two, then revert to normal.

Other ideas for earning the power-ups are welcome.

git clone git://git.debian.org/git/tux4kids/tuxmath.git