Wasn't a weekend finish, as gaming time was in short supply... but managed to finish off La-Mulana yesterday before bed. Total playing time was roughly 26 hours, which seems ok for the first time through the game.
Ending sequence was very decent. I liked how the levels changed as you were running through to simulate collapsing ruins, also altering the paths you were able to take (mostly in a helpful way except for one point close to the Temple of the Sun entrance where I almost got crushed by a huge block of falling debris). Glad I had read the messages from Mulbruk and remembered her talking about an exit - would've been frustrated if I had to go through the entire boss battle a second time.
My only regret? I started a new game afterwards, thinking it might be a good way to lower my total playtime with the knowledge/experience I've got now. Then I accidentally saved over the "just before the final boss" save. The only proof I've got of my progress is the PSN trophy, and it looks like I'm not going to be going back in to try and unlock any other trophies for a while. Oops.
Anyway, still love the game. Yes, it's got some moments of obscure or punitive BS... but it's also got a lot of fun exploration and clever ideas. It's also one of those games that you can gain a certain type of mastery over, which feels rewarding and empowering in a second run-through (even if the first run isn't as enjoyable). Super glad there was a retroactive that encouraged me to go back and spend more time with the game.