If your machine is experiencing lag issues, please take a look here.

If your machine is experiencing lag, lower the resolution and reduce the in-game frame rate. Make sure not to set the frame rate to unlimited — it will eat up CPU like crazy. Doing this will greatly improve smoothness. This is something I discovered in the past few days. For the old version, you can use this workaround for now. I will directly fix this issue in the new demo version