After realizing that many players did not like/understand the training/tutorial mission, I decided to remake it another time, now answering player's feedbacks, since the tutorial is very important to get used to the game's mechanics, like the Bullet Time, Aiming, Reloading, Manual Cover and so on.
First of all, I removed the annoying invisible walls, so that means the player is freely to accomplish any of the tutorial tasks in any other, since now, each task is independent from each other.
I also added visual indicators/markers so the player knows where he must go. Once the player reaches each visual marker, the onscreen message appears teaching the player the task he needs to accomplish. These markers disappear once the player accomplished the task.
Last, but not least, I improved the map itself, added some details, more trees and foliage, so the map doesn't feel empty/blank.
I think that now the tutorial mission is good to play and more important, it will trully help the player to learn the basic gameplay mechanics.
By the way, even though not mandatory, but it is extremely recomended that you play again the tutorial mission on the full game, even if you already played on the demo, because there are some updates on the Bullet Time Mechanics, which are not present on the demo. Also because, each mission, even the tutorial, will have a Steam Achievement to unlock.
Here follows some screenshots, I hope you all enjoy it: