Really sorry for the trouble that causing in the newest version, didn't expect the cloud shader will have such impact on the performance. I am currently working on the solution to fix the problem. Will re-upload a better performance version later.
I re-uploaded the game file. Now in the setting, you can toggle to use the simply texture on cloud and star and it should be way less costly on performance. You can also turn the fog off since it is same costly as the normal texture.