sorry to hear about that!!
after doing some research and testing, i've found out that the slowdown is actually my fault- i turned on a setting that i thought would just cap the frame rate, and while it does, it also makes other frames affect the game speed :/
if you'd like to give it a try post jam, i'll have an update with some graphics options, and as well as having the fixed frame rate option off by default, so hopefully you should be able to find an adequate play experience then!
i actually had to take a look at my dice settling method too, as the old one was breaking at low frame rates, but the new one is much more reliable and stable, luckily!