SRB2 lacks any real horror mods. So naturally there is an untapped market in making one. Tails Doll Forest (I will call it TDF from here on), does a good job as a horror mod. However, a few things are lacking in my opinion.
While the 2.1/Early SRB2 map design works well by making things cramped and tense, there is a limit to everything. The first real act took me 13 minutes, and I wasn't even going for the emeralds. I just happened to find it by looking through a path between two trees. Something I wouldn't have spotted any other time. Besides that, the maps feel a bit generic once you are out of the TD Forest. Since it's just interior, houses, and blood.
The main threat, the Tails Dolls both work well and not so well. Duplicates make it so there's never one chasing you due to the way they're scripted. But that's also their weakness if three are chasing you and you get hit you don't take three damage and knowing you got enough rings you aren't scared to die. (Not to mention extra lives can be farmed at the start, and I think there should be less since going in with 30 extra lives defeats the purpose of losing.
I enjoyed TDF but so many small things hold it back. 7.5/10