The game has a full map editor. It's not documented because the compo version is, in general, kind of a mess. Directions on the second controller change the height and texture. B+direction on the first controller will move the cursor. Select on first controller will open a hex-editor view, where directions on the first controller move the cursor, and B+direction changes height and texture. (Like I said: kind of a mess.) Start in the hex editor will change to editing the enemy grid, which is its own kind of jank.
The Suffer option just removes health. It was a debug feature I found amusing enough to leave in. I think the compo version source code even remarks on how needlessly edgy it is.
The stuff at the top is there because apparently FCEUX is not a very good emulator to develop with.
The premise so far is, to paraphrase Yahtzee Croshaw, "here be enemies, shoot they ass." The intended tone and context largely has not been implemented. I've been fixing bugs, improving performance, and adding features, since the deadline. That'll get posted when voting ends. A version that is an actual complete-ish game should be out by end-of-year.
Should.