Another shareware cult classic, Jetpack was and is a great platform game in the vein of Lode Runner and Jumpman. And there was a totally awesome Christmas edition with 10 new levels and the ability to control a jetpack-wielding Santa Claus! And no, there is no relation to the Jetpac and Jetman games by Ultimate Play The Game.
The Jetpack games are now freeware! Get them from Adept Software and RGB:
You can also download the original shareware Christmas Special: