Arrow keys move the porcupine around; the balloon will move simultaneously, but may move in a different direction.

Power-ups:

Rotators change the direction of movement to the left or right.
Mirrors reverse the direction of movement.

Time-dependent power-ups:

Grow/shrink cause the heroes to grow or shrink depending on when they are picked up.
Fast/slow cause the heroes' movement to change depending on when they are picked up.

When enlarged, the porcupine can shoot quills and the balloon can jet across the screen
for a bit.

Press Z to perform a quill attack; press X to jet propel the balloon.

Hints:

The balloon doesn't like spikes!
The porcupine has problems with pits.
Some walls can be destroyed.