So yeah, the player is now in the game, and the gameplay has taken shape. Like I hoped, the game makes it easy to break ice and press switches, and less easy to single handedly fight a bunch of enemies. If I can design some good levels, than it should be quite a bit of fun.
Also, I need to come up with a name for it. I'm thinking something like "Trouble in the Tower", but I don't know.
Since this has been the longest I've worked with XNA on a single project, it's been quite a learning experience. I've learned, for instance, that it's probably better to use sprite sheets rather than individual files for each sprite, so I only have to apply the alpha background once. I've learned things about XNA that will help when I start working on my sidescrolling beat-em-up project after Blocky Man.
I can't seem to figure out how to read from files in C# or XNA, so I figure I'll just hardcode the maps for this game. In either case, I need to find out a way to do it tonight, so that I'll be able to get the game ready for submission tomorrow. The game is in no sense polished, but it's playable and interesting.