It's a long and solid remake of Half-Life 1. The game is also quite polished. It only has a few minor glitches left. The visuals and sound effects are amazing for a Source Engine game. However that also causes quite a few performance problems that are quite heavy for a 15+ year old engine. I talking about frequent drops to less then 30 FPS on a decent PC from late 2018.

Although it stayed playable the whole time and it ran quite stable for me. I had one crash in my play though.

The game can be a challange even for Half-Life veterans, but it stays fair to the player most of the time. The levels are all bigger, more detailed and more credibly designed than those in the original game. Sometimes however the level layouts, especially in the late game, can be quite confusing. You can get lost easily if you don't pay attention.
The level layouts appropriately differ from the original quite much. The later 40% of the game (Xen) is a complete overhaul, that still matches and improves the ambiance of the alien would without having the quirks of the original. Xen part in Black Mesa is almost exhaustively long and was worth the 7+ years wait.

Conclusion: For me it is a game of the same caliber as Half-Life was back in the day. When Crowbar Collective fixed the performance problems, It would have a Valve like quality.

It's a long and solid remake of Half-Life 1. The game is also quite polished. It only has a few minor glitches left. The visuals and sound effects are amazing for a Source Engine game. However that also causes quite a few performance problems that are quite heavy for a 15+ year old engine. I talking about frequent drops to less then 30 FPS on a decent PC from late 2018. Although it stayed playable the whole time and it ran quite stable for me. I had one crash in my play though. The game can be a challange even for Half-Life veterans, but it stays fair to the player most of the time. The levels are all bigger, more detailed and more credibly designed than those in the original game. Sometimes however the level layouts, especially in the late game, can be quite confusing. You can get lost easily if you don't pay attention. The level layouts appropriately differ from the original quite much. The later 40% of the game (Xen) is a complete overhaul, that still matches and improves the ambiance of the alien would without having the quirks of the original. Xen part in Black Mesa is almost exhaustively long and was worth the 7+ years wait. Conclusion: For me it is a game of the same caliber as Half-Life was back in the day. When Crowbar Collective fixed the performance problems, It would have a Valve like quality.