Thanks so much for such a detail feedback.
The filter was here just for this reason, if someone would be sick of the point filter, but accidentally it improved vision of the player so it made the game easier. The movement of the enemy could be improved to be faster, when player is far away, but same speed when player is really close. And the pathfinding could be improved more, now it's just if the enemy sees you, it goes towards you with little bit of randomness.
But once again thanks for your comment, there is lot to improve in this game and it's good to know what is is.