What kind of phone do you have?
Viewing post in Thou, Eternal Everbloom (18+) comments
It has a processor that struggles with many games, and even though this may seem like a simple pixel art game, it has a lot of background scenes that also put a heavy load on the memory. Currently, it isn't 100% optimized for low-end devices, so try using the low graphics mode.
If that doesn’t work, I recommend playing on another mobile device or waiting for the final version, which I assume will include further optimizations.