How long ago was it stored like this? My guess is not much happened unless it's been decades. And by plugs, do you mean drain/vent screws or spark plugs? Is the motor locked up?
The boat was stored like this for 2 seasons-with the gearcase oil fill and drain plug removed-but motor was covered by plastic tarp. The motor has not run this summer well because of suspected carb fowling. Ran 1/4 speed and hard starting.
I would expect the gear case to have some rust in the bearings and on the gear teeth. It might be a better mooring anchor rather than a motor. You will have to make a first hand assessment in order to tell.
