FernStream LP - Little Samson 04 - Boss Rush & Sudden Ending
Usually when you have a "defeat the final boss, then escape the crumbling whatever" scenario, it's very clearly defined. The boss will say "But you won't escape with your life!", or a big destruction timer will start, or it'll zoom out to the place shaking and crumbling or something. Then you'll go along a path (possibly one you saw earlier in the game) to reach the exit, escaping just before the place caves in on you.
...Yet in this game, it's amazingly un-defined, it's not clear that the final boss is actually the final boss, or that the final escape is of the "escape before bad things happen" type of run. There's not even a single thing marking the end of it as the end, it just seems like the end of any other given screen. So yeah, that's what I mean by "Sudden Ending".