Japanese version added

i got the language menu added after finally finishing translating the skill names and effects to japanese.

also someone reported major lags on infinite stages so i looked into it and it turns out the monster soul particle objects werent destroying themselves so they were building up lag over time.

I also added several other anti lag methods. like, health drops and coins arent destroyed, only moved off screen.
if a new one would be created and theres already one waiting off screen, that one is used instead

ive also been approached about french and brazil localisations. but i dont know if im up for that since i'd have no way of verifying if the translation was accurate and appropriate