Hmm that is weird, i havent seen that happen before.
the characters just use an animated sprite node which is pretty common, have you had that problem with any other games?
not during this jam, though I had other types of rendering glitches on this laptop during previous jams,
but typically in 3D games in the web format. In these cases I played the downloadable version if available, which didn't have these issues at all.
I am pretty sure it is related the the age of the computer, it doesn't support the newest technology anymore. This is something I also get to feel, when I want to do something graphics heavy like rendering, it is barely possible on the laptop, so such work I do on my stronger desktop pc if available.
Otherwise I had one more minor issue on all (or most ?) games, and that is that the full screen button didn't work as well.