Okay, to everyone who thinks that the singer is a "she".
Guys can sing high too! Dave Bayley is just using his head voice. It's fairly common for male singers in this type of Genre to do that. You can usually tell when a singer is female, as they typically have a sort of higher-pitched quality to their voices. When listening to Gooey, you can hear Bayley's voice is darker than your typical female singer.