Greetings.
Many barrels of plump helmet wine to you for making this a registrationless forum.
Sight through walls and floorsThe ability to see through walls and buildings really needs to be improved.
1 - None of the four isometric views allow you to see ground in thin orthogonal alleyways between buildings.
My only idea is to make whole walls semi-opaque, but this is not aesthetically optimal.
2 - I can't shoot from one building to another mainly because I can't see targets in the next building. Otherwise I am not sure if the engine allows this, or if it treats the same floor between two different buildings as different areas ( that can't both be 'active' at the same time ).
If you do implement building to building combat, it would be nice to be able to target a floor different to yours. ie shoot people on the ground from top of building, assassinate target on 4th floor from a 3 floor building, etc etc.
On the other hand you may want to limit such things to create a different style of gameplay. This suggestion might make the game too easy.
Elevator Blindness I rode the elevator to level 4 of the quarry's building and a guard walked in as soon as it stopped at the top. He left at his floor and walked away, never noticing me during the entire process.
In-elevator combat?

Apart from a crash I can't reproduce after planting the 'electric surge' on a car I have not come across any other issues.
Thank you for providing these alphas for free. I'm a very grateful Arch Linux (x64) user.
On a different topic, do you host your own webserver Christian, or is this provided by a company?