I showed of around third of this before, but now the first level artwork for my monster collection game Powered by Monsters is finally finished!
I worked on this in several sessions and drew other stuff in between of course, but overall just the painting of this took around 150 hours. Luckily integrating this into the game engine, adding all the colliders and such is much faster.
I'm actually quite happy with this and the next thing to do will be to add some smaller randomized rooms to this to make the level a bit different each time. Also I'm sure it's hard to get the scale of this, so take a look at the secondary images, those represent how much of the background you will see in a single game screen.
This hasn't even reached the level of a demo yet, but check out my Steam and Itch if you would like to see some games I already completed:
https://store.steampowered.com/app/2887720/Human_Upgrade_Labs/
https://ultra-shenanigans.itch.io/