Finally, done. This has been educational - I've had to cut scope drastically (as I expected), but it's reached a point where it's at least playable, if rather kludgy and janky! Given that this is my first ever completed game, and first ever game jam, I'm happy with where I got to in this week! :) I even had to learn tilemaps from scratch, having never used them before (which probably shows!)
A couple of screenshots attached. Sorry for the extremely bad programmer-pixel-art!
