IW v2 is a overhauled version of the original IW. It holds little in common with the original as the 3 episodes that featured in it have been heavily updated. Plenty of new weapons have been added and there are 2 new episodes as well. One of these consists of maps made by the Duke Nukem community for both IW v1 and V2. The other episode is a much more story orientated episode with time travel and even has a choice of endings. Iw v2 uses Eduke32, an Enhanced version of JfDuke with much more coding control allowing fantastic effects. The port it is based on allows for models and high res textures which IW v2 takes full advantage of.
Screenshots of the release version of Imagination World v2.