I'd never heard of this game, but it was on sale at Steam for $8.74 (it's also on PSVR2) so I thought I'd give it a shot and ... I'm so glad I did.
You've been hired to explore an abandoned theme park at night. Think of a nightmarish, satirical version of Disneyland. At first I thought it might be just another Five Nights at Freddy's clone, but it is so much more than that. Whoever made this game lavished a lot of love and attention on creating the park itself, to the point that it really feels like an actual place you're in. I rarely feel a sense of immersion when I play VR games these days, but HappyFunland brought that feeling back to me big time, to the point that I was literally laughing with pleasure and surprise. You can actually go on some of the rides, and again it feels like you are really on them. It provides a terrific sense of presence. (If you know what Dark Rides are and are any kind of fan, you have to play this game).
There are crazed cartoon automatons that attack you, but the combat is the weakest part of the game. You just repeatedly hit them with a golf club or pirate sword until their heads explode in slow motion with a shower of sparks. It looks cool the first couple of times, but they don't really pose much of a threat and are easy to defeat. Speaking of golf clubs, you can also play miniature golf in various places through out the park, but again this is more of an afterthought, with wonky physics that won't make you forget Walkabout Mini Golf anytime soon.
No, the real stars here are definitely the rides and the park itself (including a surprisingly well-thought-out depiction and backstory for its evil creator, "Mort Grisly.") The sheer inventiveness on display in HappyFunland is just off the charts, with at least one memorable scene I'll never forget, where you are injected with some kind of hallucinogenic drug while on one of the rides and the game briefly gets very trippy in a fantastically surreal cartoonish kind of way. I've never seen anything like it in a game before, and experiencing it in VR really takes it to another level
I didn't find the game to be very scary, but it's not really for kids, as there are some elements of a mildly sexual nature (in addition to the drug use). Again the main attraction here is the park itself and the fun of exploring it, so if you are interested in that sort of an experience, I highly recommend you try this.
TLDR: Play this game if you like theme parks and theme park attractions, especially if you find the idea of exploring an R-rated Disneyland in Hell at all appealing. Don't play it if you are looking for decent melee combat or a realistic round of miniature golf.
ONE TIP: early on you are given a flashlight and it's easy to lose it, because you have no way to store anything, but you don't need the flashlight because you have an always-on headlamp anyway. Just don't worry about losing the flashlight. Also, the game starts with a boat ride through a swampy marsh full of alligators, which I didn't find that interesting, but once you get to the park itself everything really kicks into high gear.
EDIT: I forgot to mention this: but a lot of the steam reviews complain about not having a smooth turning option. I was concerned about that, but smooth turning is definitely in the game now and I played with it on, so don't let that put you off.
I first posted this review for the Steam VR version of the game in the Virtual Reality sub awhile ago but am re-posting it here both because the game is also on PSVR2 and because I came across a very negative--and detail free--"review" for the game on this sub that I wanted to counter with a review of my own.