OK, I found the golden sword and shield and then killed the ogre. It was probably a good thing I missed exactly one key to reach it (although to be fair there was more than one door left in the area so I may have used an extra key on another door) to reach it before exploring the green castle and coming back because it could have smashed me.
Overall things mesh very well, the environment looks super good and its palette and the music fit perfectly like you're playing an upgraded 8bit or Spectrum game. It was fun exploring this big map. I can't say I was super impressed by the combat but it really never unduly annoyed me either since you can kill enemies pretty fast and you're never flooded with enemies.
The game delivers simple, traditional crawling with strong presentation and I greatly enjoyed it.