It's good, and you definitely should play it if you like Half Life, but it's no replacement for Half Life. It's gunplay, enemy design (aka reskinned Combine that are more aggressive), aesthetics/atmosphere just aren't as good as the original imo.
Also say whatever you will about og Xen at least it didn't drag on for like 4 hours
Also say whatever you will about og Xen at least it didn't drag on for like 4 hours