There is a sign above the pogo stick, which reads (in Standard Galactic Alphabet): Behold the holy "POGO" stick.
Above the pogo platform, there is a secret area with fire, a garg, and a teddy bear. This can be accessed by pogoing up a set of hidden bricks on the right of the level.
See also List of Keen 1 Levels.
- Hint Sheet (Invasion of the Vorticons) under Hints for Episode One