Commander Keen 4.5: Parallel World
Commander Keen 4.5: Parallel World is a fangame by Keen fan Andy. (Not to be confused with another Keen fan, Andrew Durdin.) The first engine was presented in May 2010 with a one level demo that doesn't feature the Bean-with-Bacon Megarocket. Keen is seen with recolored clothes. The current version of the game (of which there is no download) boasts a pogo stick, various gems, and three types of monsters. Graphics are ripped from the original Keen games, but there are plans for them to be changed in future releases.
When Keen departed the Shadowlands at the end of Keen 4 he is accidentally transported to a parallel world, crashing on a strange planet. In order to escape the parallel world and make his way to the Omegamatic of Keen 5, Commander Keen must find the various parts of his Megarocket that came lose on crashing and repair his ship. This is similar to the plot of Keen 1.
There are plans in future releases for the inclusion of a simple level editor that could then be used to make new maps, as well as the possibility of including new graphics and plots.