Really wonderful. Left 4 Dead managed to strike gold as a solid co-op game that, while it feels barebones nowadays, still shines with solid enemy and level design that keeps it fun even after 14 years of its release. Even though Left 4 Dead 2 totally outclasses the original it's still a really great piece of history that doesn't get replicated as well as it should due to its spiritual successors either trying to do too much or not giving enough at all.