I am glad you are currently enjoying the concept of the build and I really hope you check out all the future updates to come.
The level design choice for first 3 levels was heavily inspired by the original Doom but I wanted to make it more 'Hell-like' if that makes any sense, if you look closer at the wall, floor and ceiling designs of the game you'll notice that they are edited pictures of real life rocks and minerals like the original Doom.
The Idea for the Imp was for them to be the basic first demon of the game that on their own they aren't much of a threat but as a group they can easily overwhelm you. I also made the decision to have them first up as they are in most Hell depiction canons to be the lowest ranking demon spawn in Hell.
As inspired by the original Doom I wanted to captured that 90's pure nerd feel of having Midi versions of famous metal songs throughout the game, the first 3 levels feature midi tracks from Judas Priest as I felt like it would fit the vibe I was going for. The source of the music used can be found here: Metal MIDI: Download MIDI Files.
Due to the Engine choice a lot of the 2D sprites turn along with the players eyesight akin to Wolfenstein 3D hence the perspective can be awkward at times and for this I apologise, I do aim the add more details to the Imp models long term to emphasize changes.
It may appear the Imp models are shrinking down when defeated and I can explain what is actually happening. The Imps are flying in this universe as inspired by flying Imps in the game Elder Scrolls IV: Oblivion and I took to the idea hence the walking models are flying models. Upon defeat an Imp gets so gravid and heavy they can't fly so the end up ground bound and exhausted from the excess weight they're carrying.
Due to limitations with the Game Engine I am using for Hellspawner unfortunately the weighted player idea sadly can't happen but thank you for the suggestion as it is something I myself would like to do maybe in a different project in a different engine one day.
I would like to take this opportunity to thank you for your feedback and I hope to expand upon it in the future :)