DayHard is a single player modification for Half-Life 2 which places you in the shoes of Gordon Freeman's not-so-famous brother, Morgan. It's a comedy/action adventure.
DayHard Video Review: Youtube.com
While DayHard is extremely flawed in various parts with broken triggers and scripted sequences along with gameplay bugs, its compensated by a great and unique buddy story in one of the most unique settings in any mod, let alone any other game I have ever seen.
It's very fun, does its humor really well, and the music is great and catchy. This mod has reboot potential and hopefully the devs can come back and make another DayHard esque game in the future.