Hi!
These are all know issues, which are being addressed to varying degrees.
For the first issue, it may be that your computer is below the minimum specifications as listed on the download page. On the Discord server, there is a LowSpec build in the works that should address this.
The shooter minigame difficulty is also a known issue. It will probably be improved with the Chapter 2 release. The logical issue is also planned to be fixed with the Chapter 2 release.
As for the 40 minutes, those are the amount of time it took Diana to notice Wolfgang and get a reaction out of him. The flashback is meant to condense those 40 minutes.