I've been playing Zelda Classic this afternoon. No noticable bugs that I could spot either, although in windows 7 (and presumably vista) it does turn the aero theme off temporarily while it runs:
http://www.zeldaclassic.com/downloads.phpFor anyone with a Mac or Linux (except gentoo), both versions of those run pretty well too.
You can add some fun custom quests too which is interesting - currently got the linux version running on an old PSP - it is a lot of fun
