The Hell Factory was the introduction the community got to TeamN2 and their megacollabs. It's quite derivative in theming, even for how old it is. Even so, I'd still label it as one of the classics as far as extreme demons go.

Visually it's not too special. It's got par for the course hell decoration for 2.0, with woogi's part probably being the best designed in the level. Other parts such as the opening ufo by reple, Cosine's clubstep monster ship, and ryanlc's maze are also iconic when you think of this level.

In the gameplay department The Hell Factory was a surprisingly enjoyable experience. It's certainly not as well balanced as modern day levels, but its unbalanced nature isn't to the point of unenjoyability. Some of the scarier looking parts like the aforementioned maze get 100% consistent when learned and aren't a roadblock. Woogi's part was definitely the hardest in the level, but it too gets consistent with enough practice. THF is overall a pretty fair level that doesn't catch you off guard with extreme difficulty spikes, unlike its sister level A Bizarre Phantasm.

The Hell Factory is a relic of a different time in this community, and I'd overall say it's worth your time if you like old styled gameplay.