I know this is a reallllly long way off but Casey reiterating that the primary mechanic of the game is that players deal with one room at a time got me thinking about a cool boss mechanic.

So for an ultra-powerful boss (maybe end-game boss not sure) I think it would be a cool idea to have this one boss be able to hit the player hard enough that the handmade_hero actually breaks through walls and spills into multiple rooms like so:
______________________________
|Go Back Through, Handmade_Hero|
V

| | |
\ \ \
================================-K
/ / /
| | |

but where the damage remains as a permanent scar on the land.

Considering the name of the game is Handmade Hero, I'd imagine that Casey has a good deal of introspection in mind for the actual story of the game. With this in mind, I think it's a cool idea for two reasons. First, on the shallow understanding of the event, this boss has the power to actually bend the fabric of reality (for the characters in the game) to it's will by actually creating a hole between two separate rooms. This is powerful in and of itself because presumably at this point the player will have a thorough understanding of what to expect in the game and having this as an event will really throw the player off guard (maybe even have the puzzles of the room mix into a super-puzzle with combinatorics, as Casey mentioned would be utilized).

On a deeper understanding of the event, the core mechanic of this boss is literally turning the game from what Casey (and I'm sorry if I'm putting words in his mouth, this is just my impression) may see as a good game in the genre into a bad game. Perverting the handmade hero into being the tool that turns the game world from closed-scope puzzle-adventure, into an open-world hand-holding adventure (note the ASCII message is part of the bosses attack) one attack at a time.

I don't know if I'm completely missing the point here, we were just talking about the core mechanics of the game and I thought it might be fun to find a reason to break them a little :)


EDIT: sorry about the awful ascii picture, its really hard to format it right

This might be a personal opinion kind of answer, but I've always considered good boss designs in games to be those that made the game mechanic of the level less forgiving (whether in space, time or logic wise). As such I believe coming up with boss designs before knowing what the level they appear on to be premature, let alone before we even know what the Handmade Hero game mechanic will be.

That said, I do think the game mechanic you have presented is interesting on its own, and could be adaptable to many different mechanics (one of which you might develop if Casey's game ends up being very different from what you currently envision).

No not a problem, I appreciate your opinion! I mean, a great deal of what I was proposing was admittedly based upon pure speculation on my part.

I completely agree with you about this being very premature--I guess what I was most curious about after making the post was wondering what people thought of the idea of pointedly breaking a core game mechanic as a mechanic itself... if that makes any sense.

I think you gave me the best response I could have hoped for, which was to share a good mindset to have when designing a boss mechanic, and give your honest opinion about the idea, not necessarily the implementation.