It's big, dumb humor that's smart enough to not be grating and smart enough to not act like it's smart enough, which keeps it from getting annoying.
There isn't quite enough here to knock something like Doom Eternal off its perch, but if you're craving a different style of FPS, you should check Serious Sam 4 out. It puts you in fun scenarios with plenty of monsters to destroy and plenty of clever ways to destroy them.
Serious Sam 4 isn't dramatically more than you'd expect from a Serious Sam game, but it does what you'd expect extremely well.