The ghost unstable trail is a trail that cost around 100B steps tied with super lasers price Obtaining this trail gives you access to the best island so far, Ghost City. The stats are almost tied with super with ghost having a higher jump power. You must open the ghost unstable crate which randomly appears at the unstable shop "Chances of it are coming are low since there are a lot of unstables"
FYI if u want to buy it a friend told me it only appears on wednesday idk if its true or not.