Mods / difficult

• CCrowded Houseby 76561198809220274There’s been a noise complaint at 226 Flaccid Drive, time to go break up the party. My first try at a level, so I hope you all find some joy in it105 downloadsupdated 6 y ago
• CChaos Insurgency Raidby 76561198902410920Control to 1-1, Epsilon-11, requesting reinforcements at Site-19, multiple Chaos Insurgency members have taken over the facility, most scientists are in the evacuations shelters. The insurgency wants to detonate the Alpha Warheads so be fast.76 downloadsupdated 4 y ago
• TThe Mansionby BadExperimentSuspects have taken the mayor and his family hostage and threaten to detonate an explosive. You have 5:00 minutes to defuse the bomb, then get the mayor and his family to extract.68 downloadsupdated 4 y ago

3 difficult mods, most downloaded first. Each one has its own page here with what it needs to run and where its author publishes it; the files themselves stay with the author and are never re-hosted on this site.