Really enjoying this. I played Infested about a year back, which I enjoyed quite a bit, but this one really nails the creepy nature of Shadowgate and Uninvited (and to a lesser extent, Deja Vu), with a little bit of Myst of all things thrown in. This feels like an instant classic.
And the soundtrack is wonderful! At first, I thought the not-exactly-NES style music would be better off if it were more in the style of NES chiptune stuff, but the two "field" themes in particular are so good and atmospheric that I can't imagine it any other way.
One suggestion I might add: Shadowgate had a feature where if you pressed Select it would give you (sometimes) a vague context-sensitive hint based on the room you were in. I think that'd be neat here.
Anyway, I'm stuck at the Guardian just to the right of the throne room. I thought the solution was obvious based on The Uninvited (and I have something in my inventory that should do the trick and get him to go away) but alas, it's not that simple. What should I do? I know there are some items you need to USE on SELF (and I've got two of them), and I feel I'm missing a third that's necessary.