Yes this is the game! I also changed the topic title. Thank you folks!
The game was released at the end of 1998. It is possible, that the demo I played is an earlier version, but I remember definetly, that my PC was very old for that game. According to some website it needs a 233 MMX cpu, what I did not have that time.
Now I watched the videos, and I remember the breasts of the female character, and the tattoo on it 😁 It was crazy for a young boy teenager, controlling a female character.
This first-person-shooter game new idea (at least for me was new) that the objects (rocks, cans, clubs) are moveable and throwable. And there is a phisics engine which handles the gravity if you push an object on a tilted surface (like a wood box in a tilted wood board).
I just learnd about the fact, that during aiming with a pistol you can rotate your elbows and hands, and that's way you are able to shot yourself 😁
There is a rock-throwing physics but (according to a player) it has no use. And when you do need it, there is no crosshairs, so can never hit a target easily.
According to a website forum:
" development started before 3dfx Voodoo 1, some techniques, like the bump mapping and image caching were incompatible with graphics processing units. Because of this, i.e. bump mapped objects are drew software and the terrain in hardware. Additionally, number of texture in mip-map was so big (used by software mode), that even Voodoo2, could not handle. Thats why hardware mode is using the lower resolution textures."
On website: https://fabiensanglard.net/trespasser/index.php
"(The game...)Released in October 1998 after a three years development cycle, it was unanimously destroyed by critics. But it did not fail by much and managed to grow an impressive mass of fans that wrote editors, released patches, reverse-engineered the assets, added features, produced new dinosaurs, levels and even started a remake."
Introduction video with commentary:
Awesome game. I will try this game out.