Here is my mod's story;
First of all you are Gordon Freeman.:)
At the end of Original:Half life gman(the guy with blue jacket) says ''...we have controlled Xen...'' so in my mod ;
The people on earth builds a city on Xen because the aliens are under control but one day everything goes wrong aliens get out of control and attack the city...So gman wakes you up from your life bubble(a big bubble in Xen) and says :rise and shine freeman and then he talks and talks .After that you enter a teleport and teleported to Xentopia the city on Xen.
New Monsters(NPC)
S.W.A.T: Like hgrunts but named S.W.A.T (thx to Mike Verret[Unbreakable]
DEMONGARG: 3Gargantua=DEMONGARG a black and giant gargantua
Missle Turret: Like turret but fires missles...
X.R.V: (I dont know if this monster is possible in the game[working on it])
U.F.O:like osprey but for aliens
invisible zombie:_
invisible houndeye:_
bloater:A xen creature that always meditates but dont get to closer to them they can fire beams.
chumtoad:A purple ,one red eyed frog that expolodes when you came near it.
screenshots: sory they are kinda big