Having installed the game straight from stream, experience was poor even though even in that case game is somewhat playable (10FPS, dark, 800x600 resolution, slowness, no possibility to open menu when in game).

To fix that, I have applied T2Fix (https://github.com/Xanfre/T2Fix) with mods (my preference, you can apply fix without mods). After applying fix the game was fully playable, with good video resolution and gamma, constantly at 60 fps. Menu was accessible, text was more or less readable. Was able to complete a couple of missions (hello, shoulsgate).

The only bad thing is that you'll need to spend some time to customize controls to be able to have good playing experience. But other than that - game plays very well.

Another note: to apply T2Fix, after I have downloaded, I tried to use wine. It was proven not possible, so I've run that executable by adding it as non-steam game.