Maze of Galious!

Consider this both a discussion for Maze of Galious (and related games) and a place for me to shamelessly ask for help on a game I've never played before. :P

I was reading an article about "metroidvanias" recently which went over the history of that gameplay type. On the entry for La-Mulana, Maze of Galious was mentioned, and Cave Story was mentioned earlier on in the article. I was pretty curious about each of them, having never played Cave Story extensively, and admittedly having never heard of either Maze of Galious or La-Mulana. I'm messing about in Maze of Galious at the moment, hence the thread! I'm playing the fan-made PC version. It's a really addicting game so far!

Now for the shameless question. The things that look kind of like brick walls... Are they... doors? If so, do they open? @_@ I'll figure it out eventually! *smashes keyboard*

So yeah! Maze of Galious! Anyone like it?