I've got a performance issue too. The version I pulled down was the latest I saw = 1.07.
I wonder if it's NVidia specific? I know of one other game having framerate issues on NVidia.
My PC is a 2009 vintage i7.940 @ 2.93 Ghz
Win 10 Pro x64
12Gb RAM
MSI NVidia 970
1920 x 1080 27" monitor
Response seems slow in the starting selection screens, and movement within the levels is also sluggish.
I've posted a youtube capture:
Note that upload should be complete in about 3 mins. Please let me know if you have any other questions.