Thank you for the extensive description, i REALLY appreciate it! I didn't have someone to play-test the game so I couldn't figure out lots of the point you said, and for this I'm really grateful to you! As you said the input changing mechanic should have been explained better, I forgot that it's not intuitive if someone plays the game for the first time (though the effect I wanted make the player feel stressed for the numerous death!). I know there is an input lag, it was due to the post processing quality, the game should run smooth at medium quality, when settled to ultra is a bit laggy (I didn't have time to optimize it, but I will do it for sure in the future). Yeah the split screen mechanic is something I knew would have caused different opinions (someone likes it, but it's also normal to dislike it!), the main idea was to create a game that could be played either in single player or in local multiplayer (it's really easy if you play as two), but for sure I will try also with horizontal cameras!!
Thank you so much for the feedback and for playing my game! :D