@notgreat The input lag is implemented on purpose to prevent the player from running into himself when changing directions too fast. Some people told me about that but for some reasons, I have not experienced any problems in the developing progress. Maybe I don't have problems with missing inputs because I'm used to the controls too much. Changing that would allow instant turns which would cause you to run in your segment right behind you and die.
I know it's really hard that you lose everything when you die but that's the base mechanic of snake so I'd rather lower the costs of stuff than removing that feature.
I have no excuse for the last thing. It's hard but I like it that way. I just gotta admit that things that seem self-evident to me may not seem that way to other people and I gotta work on that in future projects.
Thank you for your very detailed critics. I'll definitely consider them in the future but I can't change it in this game anymore because I don't have a permanent license for GameMaker.