Helios is an amazing level with an amazing song. Looking at you Terraria Calamity fans. (I'm one of them.)

it has some unique aspects despite being a generic glow level

Honestly, it's mainly just a purple and yellow level so it's not much interesting in the deco department. BUT! I will say, I highly recommend people go for this if you want a good first extreme demon that isn't the common joes (Acu, The Super Hotdog, Cataclysm, etc.) as the gameplay in this one is beginner friendly for an Extreme Demon. The main thing I'd say you would have to worry about is some of the timings in the level especially at the fourth part.