This reminds me a lot of every single platformer for the Spectrum. Especially Ghost Hunters, for some reason. Which is also a Codemasters game. Yes, i know there was a Spectrum version of this too, but I never played it.
Anyway, you explore a castle, collect treasure, and eventually reach Maid Marion. Except when I got there, a ladder to reach her was broken. Turns out, you have to get all the treasure to fix the ladder (for some reason that isn’t explained). Of course.
So I had to spend half an hour backtracking (thankfully I’d killed many of the baddies and opened a few shortcuts so it wasn’t as bad as it could have been) and then another half an hour returning to the final screen again. With the ladder complete, so was the game!
Not a fantastic game, but a more than competent 8bit platformer. Providing you don’t miss any treasure, obviously.