looks like the cam belt snapped, there is a significant sign of impact on the pistons and the valves that are not seating have piston impact marks. might get away with replacing the damaged valves. always a bad thing for an engine, i have both scrapped and repaired engines like this and the amount of damage really depends on so many things its hard to tell. Best of luck to whoever takes this on, i am hoping i won't need to go this far, fingers crossed.