I actually saw that one back in college. I'll at least give Hoskins full marks for doing his best given what he had to work with, and casting Dennis Hopper as King Koopa (as he was known at the time) was a special germ of either madness or genius. The movie would be entertainingly bad if it wasn't so dreary.
If anyone is curious, Rifftrax did a fairly good run at the film some years back, and that's the way I'd recommend watching it.