My game has no pictures whatsoever, but it comes out to 23MB. There is no unused code. It doesn't seem like that big a game. Maybe a 10 min playthrough. Is it common to have to delete part of a game to upload it?
Just a guess: If you ever added pictures, audio, or video, the files are probably still in the game's directory (even if you removed them from the game's code). Anything in that directory will be automatically added to the game when you build it. So, maybe you need to delete unused image, audio, or video files?
I'll try that when I get home. I only ever had two images in the game, but when I went to pick a cover image, the dropdown menu showed a bunch of other images in my documents folder.
Be careful and make sure you don't delete anything that you'll miss!
The only files that count are the files in your game's directory (the same folder as the .aslx file). The path should be something like "C:\Windows\UserName\Documents\Quest Games\Game Name"