These small drones use coreless motors in which the brushes are simply brass fingers. With the high current and inevitable sparking between the brushes and the commutator they gradually get burnt away. Probably a prop was jammed when it got stuck in the tree and that was the last straw for it.
With care, it’s not difficult to disassemble, and you can get a set of spare motors from AliExpress quite cheaply. It’s a fairly delicate soldering job to install them but not hard with care.
For more info see https://wiki.restarters.net/Quadcopters_and_drones