A passionately developed love letter of Valve's Half Life.

I strongly recommend that you play the original Half Life before you play this!

The ebb & flow of combat has been adjusted, making fire fights more tense than the original. The movement system also feels slightly different in a sense of it being closer to a twitch based shooter. Enemies do feel slightly more spoungey than the original. The devs have added many new game play mechanics and environmental puzzles. The environment is well detailed and has a great sense of environmental story telling. Currently at this point in time Xen has not been added yet to the game, though according to the devs it will be released later on in the year. Some of the writing is cliche, and sometimes NPC's spawn in with their AI not activated. Occaisional audio glitches do occur. but the biggest problem with the game is it's optimization, this is most noticeable when playing the 'Surface Tension' chapter (I had experienced major framerate drops and stuttering, using a Nvidia GTX 1080 Ti and a Intel i7 6700K).

But, all in all, this is a pretty great passion project made by die hard Half Life fans.

I strongly recommend this game.

quick edit: The game has had multiple updates improving the performance and tweaks balancing the game. Still a strong recommendation.