A lot of the people making games are amateurs with no real budget, and don't pay for/can't afford the bandwidth costs associated to uploading their games to filesharing websites. Animations and pictures take up a lot of space (comparatively). Remember that the creators of games are aware that shit hosting sites make the free users strain the files through a fucking soup strainer before getting the file. So in general people don't like to make massive games with lots of animations or pictures. (the exception being rpg maker games, but those are smaller because of RTP) Take for example, slavemaker. It is an absolute pain in the fucking ass to download because the hosting sites give ass download speeds, and it has a shit ton of pictures. NOT ONLY THAT, but each slave pack might be split up into 250 mb rar files, so you might need to take hours or days to download a single slave pack or fork over money to a hosting site.