I get the concept for the game, in fun factor it was a bit missing for me.
Although, to be fair its hard to make stealth games like these very fun. Might also be personal
preference on my end. Execution of other elements was done well.
Some feedback:
It isn't really clear its a "Marking" you place on the tree.
Having some sprite to indicate that its being retrieved would already make it a lot more clear.
I was initially spamming Z and X to see if it worked or not