Lost Coast was a tech demo that Valve created to showcase HDR lighting (High Dynamic Range) in the Source engine. It's not canon to the rest of the Half-Life series and extremely short, although it is more Half-Life to play and well made, so it's a nice treat.

this was fun to play, i already played lost coast on HL2 but this standalone version was fun and will always be fun to replay. its really short but in a good way. a great way to showcase the features of the game and i dont know what to really say other then its iconic!