As a long term player of GC1, 2 & 3, I've wanted to like this game and I've refrained from complaining throughout the beta releases as that's just what they are - beta and buggy and the devs are well aware of the various bugs that need fixing.
Alas, it's now released at ver 1.01 and it runs like a absolute dog on my machine - it's so slow, with so much lag between mouse moves and clicks that it's unplayable. If I reboot my machine, it'll run OK for perhaps 20 turns but then gets so bogged down and frustrating that I've no interest in playing further.
I have a Core(TM) i9-8950HK CPU @ 2.90GHz with 32Gb RAM and NVIDIA GTX 1070 (not exactly top of the line anymore, but it's no sloth either).
When the game's running, the CPU useage on the GC4 thread peaks at around 10 - 15% whilst GPU usage maxes at 80-100% continually (regardless of whether the game is in the foreground or not). Memory useage seems to max out at around 4 to 6Gb (so it's not swapping). (Task Manager Screenshot)
I've tried "small" galaxy settings, reducing the resolution from 4K to HD - nothing changes changes the poor performance behaviour.
I really hope you can fix this as I really want to see GC4 build on the success of its predecessors.