poke646 is often hailed as the best hl1 mod ever.
I hail it as 3rd best.
the graphics are amazing for hl1. not as good as Paranoia. But they look good.
One thing, the game is short, about 5 chapters, the first level is VERY good. But the final level is not very good (not the xen level)
Other than that the rest of the game has good design.
OH! and theres a SEWER LEVEL..grumble. also invisible walls. sadly quick time events aren't here to complete the package.
The worst part of the game is the train ride, the idea is cool, get to the back of the train and disconnect it. It's execution is terrible. The ladders are bouncy,the jumping is terrible and when you get to the top of the train there are TO many hazards.
but the game is VERY hard. Play on easy first, you won't regret it at all.
FINAL SCORE: 9.0
EDIT: I recently played it over and the ending makes up for the train. The score has been raised to 9.0