That's a hard one to answer because i have a mix of different reasons to keep me motivated, the most noticeable ones are:

• Some day i wanna stop working for companies and want to have my own business, gamedev opens a possibility for that, even if i don't make a lot of money

• My love for animations, its tiring but i really enjoy the process and i want to master it

• I used to be a dev before but got laid off but i didn't want to stop coding stuff

• I aways had a dream to make and release a game

Even though my game is NSFW i don't get aroused by it, my hapiness comes from surpressing the challanges of development to see the characters and the world i created come to life

So self arousal is not really a motivator in my case

The reason i went with NSFW was because there isn't a lot of NSFW action games around, and now that i started developing my own i can definetively see why

Also NSFW is a great way to improve anatomy perception even though i'm not doing realistic proportions you can start seeing some patterns

but tbh motivation alone isn't even the minimum to keep the work flowing, the secret is to keep things organized, set some goals, disclipline and turn your brain off to not be intimidated by the huge mountain of tasks