"Is this level dangerous?" No!
I see it happen so much! People saying Level Fun is dangerous! Extremely so! So I, whom have experienced it myself, a humble wanderer, unbiased by any group... (Why would you blindly believe some people with clear ulterior motives anyways??) Will tell you the truth they try to hide! =)
I've seen it so much, Partygoers as predators! It's plain wrong! They're very common prey, often picked off by Skin stealers and even Facelings! (Wow! Not so civilized now are they? =) ) Partygoers are very docile despite being bullied and pushed around, and they're very friendly to visitors!
From my experience, they are very sweet!! The second they notice you in Level Fun they'll be happy to provide you with all types of food and drinks to help you keep satiated! (And why doesn't love a party??)
Ooh! One of my favorite things they offer other than the cake is something called Rave Juice! Almond water but 10x better!
No, Partygoers are not a threat to you! They're awfully misconstrued and docile creatures, why would a poor prey creature attack you? =)
So don't listen to people telling you Level Fun isn't safe, the locals are very friendly and happy to receive party guests! They have plenty of healthy food to go around to keep you fed for months! So if you ever see any balloons, confetti, anything along those lines, make sure to check it out! It may just lead to the best place in the backrooms!! =)