You're apparently not the first to say that, and I'm looking into it right now because I honestly didn't expect anything but that from Renpy.Can also confirm got a rather large memory leak, near 32gb before it crashed and caused my system to lockup. Does not seem to be animation related. You can load up a save , let it sit there and the memory will climb on its own but not always.
It worries me a little, to tell you the truth...