It's look like generation of floor issues.
And yea, game is 1564 pixel.
why
Over 90% of desktop users have 1920x1080p screens or smaller. You need at least a 4K monitor to play this pixel art game. This really limits who gets to see and play your work. I have no experience with gamemaker but I seriously encourage you to have an entry with a more common resolution and have it be scalable to fit more monitor sizes.