More random critters: a blue rolling cube and a glowing firefly. They can be used in vanilla KS levels.

 

The firefly is similar to the CO I used in Exploring the Golden Land, but this one has a different movement pattern and is somewhat more detailed. The ZIP file contains multiple colored versions (yellow, blue, green and pink), and includes code for two different objects based on the same animation (this is so you can mix up multiple fireflies on the same screen without all of them moving at the exact same speed).