Named Game of the Year by over 50 publications, Valve's début title blends action and adventure with award-winning technology to create a frighteningly realistic world where players must think to survive. Also includes an exciting multiplayer mode that allows you to play against friends and enemies around the world.
Gordon Freeman wakes up abruptly from the fact that he plane is flooded with zombies.
The plane itself isn't bad but there are tons of monsters stuck in geometry.
I was trying to arrange the headcrabs so they could jump.
You can try making brushes illusionary next time, that way they will be visible but non-solid / passable so the monsters won't get stuck.