added difficulty settings

several playtesters gave feedback that the game was too hard so i implemented difficulty settings

that took longer than anticipated and I appear to be paying the technical debt I incurred by using the strategy of "make it work by any means necessary"

I'll probably be sending some time re-factoring because I'm doing to need more of an infrastructure to implement the feedback I've received and my own ideas about where the game should go

to help motivate myself I'm going to put off improving the vfx until the qol stuff is done

the game is to the point where it would benefit from some music and sound but I have a lot on my list and don't want to get distracted by that yet

edit: I left in a debug command.  Hitting "leftshift + escape" ends the game to better test the high score settings