Extra oil will build up as carbon and become trapped behind the piston rings over time. They are then pressed outwards against the cylinder walls creating hot spots leading to the engine slowing down and stopping as aliminium from the piston is picked up and and spread around. Otherwise not to serious
. Rogue wave has a Tohatsu 90 that suffered a similar fate though for a different reason if you want to see what it looks like.
Suggest you use the correct mixture in future.