This mod is a very unique one. Unlike others the mod has an amazing story and challenging gameplay. The puzzles are tricky and the map design is flawless. I would honestly pay for this mod, probably somewhere near $20. The soundtrack goes very well with the game and setting. If you like the half-life series you should definately play this, its basically half life 3. I recommend playing on hard mode if you have played the original half life, but the best part about this mod is even if you dont want to play hard mode for a challenge you can just play easy and experiance the amazing story. Its very inspirational and makes you think about the half life universe. I dont think i have much more to say, just an amazing mod to play to have a good time.