He can't test it because he doesn't have a Mac or Linux. Give the man 5 fucking minutes before you start complaining about a FREE game that he made for US.
i understand how he cant test the mac version (kinda) but then again he can make a mac vm (then again i heard they arent easy to make) to test it on mac and use something like wsl to run the linux version still dont think everyone should complain like children tho
Make the size SMALLER go to navigate to Setting and click Video and click Resolution and choose a smaller size that you are Comfortable in and turn off the Fullscreen Mode and BOOM! No lag I tried it out myself and I'm the one who found it.