2018 UPDATE
I have updated the Anniversary Edition wad to the ULTIMATE EDITION pk3 and have made other changes/additions:
CHANGES FROM ANNIVERSARY EDITION:
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-Fixes all known bugs/inconsistencies from the previous 3 wads, removing all known errors and unused resources from each map
-Updates to every map adding new secrets, texture and/or map changes, and powerups not previously present, including a new radiation suit
-New enemy that appears throughout the maps, which increases the overall monster count per map
-New weapon sounds(excluding chainsaw and fist) and other sound effects(removed taunt sound due to GZDooM incompatability)
-Updated ULTIMATE EDITION graphics for weapons, menus, and statbar, including custom "F1" screens for each map, and a new color palette
-5 "new" secret maps; one playable secret level as well as two "race against the clock" challenges, split into two maps per challenge
-"Remastered" soundtrack of the original MIDIs played through the Fluid R3 GM/GS soundfont converted to OGG format, with new music for the secret levels
I recommend you play this in GZDOOM, but it was tested with the latest Zan dev build...
I have also provided a video of one of the Escape From Planet Xeon III maps in development by IDP as well that can be seen here.
DOWNLOAD NOW! (hosted by IDP)(EDIT: if you downloaded before 8/28, be sure to re-download the FINAL version)
Here are some (2015) XE3 pre-alpha screens














