I played it using an autoclicker and its not that bad to get to lvl 100 that way, it takes lika a week the first time but then you just leave your pc on while you sleep farming for red gems and you can upgrade your guild a lot and that makes it really fast to get there the next time.
Btw at first I also thought it was only the still images as a reward (if you can even call it that) but it turns out there are like 5 videos (4 of wich are 5 seconds long) for 3 girls wich is laughable considering the amount of girls there are.
The only way to get these videos is by participaiting on the ranking wich is dominated by at least 3 whales always at the top wich makes it impossible for anyone esle to get all the scenes since the last animation is unlocked with an item you get by ending in the top 3.