The Festival is a Doki Doki Literature Club mod where Monika doesn't mess with anyone's personality; instead, the festival goes off smoothly and the club gains a new member. But it's not going to be all happily ever after just like that...
The mod is short; probably about 1-2 hours of playtime. I'd definitely recommend it. The story isn't emotionally powerful like the original game or The Good Ending mod, but it's fun. You get to continue messing with files, see a lot of new poems, tangle with a believable villain, and work with Monika in an attempt to save everyone.
I have just one criticism: the secret-keeping. This is a very common thing in DDLC mods. After you restore the file of the girl that Wallace tampers with, Monika says she has to "get her out of here before she sees too much". The right thing to do would be to tell them all the truth. Still, it's better than in ABND and Shattered Worlds, because at least here there's no overarching malevolent force that the girls really need to know about, so at least the claim that they don't "Need to know" is factually true.
There's also two secrets in the game files that I'm aware of:
wallace.chr is a plaintext file contianing a meme.
When Wallace tampers with one of the girls, her file is replaced with base64 data translating to "Get out of my head" repeated a bunch.