A 5 mission beta version. The 6th mission is in there too, but it's as of yet unfinished and doesn't really work. Extract the file to your FreeSpace folder and then run the launcher. Hit the mods tab and find the mod's folder. Click OK and hit run.
Once you're in-game, go to the tech room and click Mission Simulator and then Single missions in the lower left hand corner.
The order of missions is following:
titsbeginning TITSshort tits_3 tits_4 derpable
You should play them in this order if you want to play it properly. I'd normally make a campaign file for it, so you don't have to do this manually, but I cbf as this isn't the final version.