make it so that with every upgrade you get a little health, like when you get the speed upgrade, give 5% hp, and when you get the health upgrade give 5% speed, otherwise you either go way to slow or get killed if your above ground long
"we're sorry, the stairs are unavailable and the elevator only goes between these 3 floors, and these weird monsters are attacking every floor, please remain calm, chainguns and lazers are available for purchase in the gift shop. have a nice day!"