Empty Pockets Challenge

The challenges on here are really exciting, and they got me wanting to try and think up one of my own. So I give you this: the empty pockets challenge!

EDIT: changed the rules so that you have to complete BOTH endings, and made it so you can obtain but not SPEND money.

The challenge is to complete both endings without using the inventory or the inventory book in any way and without spending any money during the course of the run, though you may obtain it by, for example, using the green gun to remove a gem in your way. Also, you may only use one master key.

The idea with this challenge is to find the most effective way to amass the required stuff without visiting shops. The less doors you unlock, the less areas you visit, the better. This isn't part of the rules, but I think it'll be a lot more fun as a challenge if you think of it that way.

I'm gonna make a video of me doing this run in case anyone wants to see how I'd do it, but I don't think it'll be difficult to complete. The real difficulty is in finding the most efficient and/or interesting solution to this problem! For although playing through the whole game methodically would indeed be a solution, it would definitely be the slowest. I like how The Village Is Lava forces you to kind of play around the game, and I wanted to see if there was a way of doing that kind of thing that didn't involve farming the master key repeatedly. Hopefully this can turn out interesting too!

I did a failed playthrough- it's not very fast, so just take it as a proof of concept.

I got pretty far (G key + all creatures but the purple alien), but ultimately failed in the Z cave, when I accidentally shot this damned gem:

with the use gun. Had that not happened, I would've gotten the spike block out of the way by throwing the gun at it. (EDIT: that doesn't seem to work)
I might revisit this some time.

EDIT: Do the rules mean "no obtaining money, period" or just "no spending it anywhere"?

oh man I've been in that position too many times to count xD

The rules are that you can't obtain any money, but if you do accidentally obtain money, then just don't spend it and it'll be okay ;P

EDIT: scratch that, it seems unreasonable to ask people not to shoot that gem when it's clearly the best solution, so i'll change it to you can't SPEND any money.

I somehow completely missed the hyperlink in your post! I'm watching your run now and it's really cool  I know the pain of having a shooting creature go rogue in the save room (tOO MANY TIMES). I wish I'd made the rules clearer from the start cos you were on a great run up until you shot the gem!

I did a speedrun of this challenge and I completely forgot about the white shooting creature in the P building! If you watch you'll see why haha. Next time I do a run I'm definitely gonna get it from there. I wanna do a slower run that is efficient in terms of rooms visited, cos I feel that such a run may be quite different from a run that's efficient for time.

https://www.youtube.com/watch?v=IgKspk5kYhA

It was an absolute nightmare to do because dying before the Zoo ending not only meant losing time but depending on how I died, often meant losing animals too. I don't think I'll be trying too hard to do this one again cos as a speedrun it's a goddamn nightmare xD