A gate next to a Key platform
Gates are obstacles that first appear in level 4 of the game Cheese Dreams.
They are green, and have small green holes on them. They may have a purple ↑ or a purple ↓ depending on what way they have to go into the wall.
When approaching a gate, they will always be seen closed, preventing the moon from proceeding to the next area. By having it land on a wheel or pressing a key switch, the gates will slowly begin to open. Usually, they will remain open, unless a mouse is in the wheel. Since the space mouse is capable of re-closing the gates, the player has to open them wide first before quickly making a bounce through them before closing.
If the player gets a certain distance away from the gate, the gate will close. It can still be opened again, however.