User Mr. Wexor played the game and reported to me that his gameplay hours were not being counted on Steam. This was because Steam understood the game's "initializer" (which only ran for about 1min until the game actually started) was the actual game. The user even reported to me that he managed to work around the problem but that made his save games not load and his method did not work on my machine.
So I decided to kill the launcher, went into the game's init scripts and added a video in the game's own internal folder to be loaded when the player actually starts the game. Steam now counts the player's gameplay hours and shows the initial cutscene normally.
I took the opportunity to increase the damage of the MP5, FAMAS and AK-47 weapons that were practically unusable. Now fixed!
If your game doesn't update, just uninstall and install again to play this new version!