- fixed bug where 2 margwas spawned on the second margwa round when it is supposed to be only 1

In line with the rules for the contest I have only made changes that are either bug fixes or balancing:

- buyable ending points required decreased by 75%
- buyable ending spends all your points instead of donation, as that led to crashes
- fixed some sound volume issues
- updated lake freeze trap text hintstring for clarity
- objective text stays on-screen longer
- added toggle for neil breen voice quotes in spawn (in case YouTubers such as Noah are worried the quotes could lead to copyright strikes [though personally I think that's highly unlikely, Noah had said he wanted the option])