When it was announced that The Binding of Isaac: Rebirth would feature difficulty levels, many assumed that there would be an easy mode that would take away the challenge that made Isaac so interesting in the first place. Creator Edmund McMillen agreed, so the difficulty levels will only make the game even harder.
Tied to this new difficulty system are a number of new items and achievements that can be unlocked by playing it. If you do an achievement that is available in both normal and hard mode, doing the hard mode version will instantly unlock the regular version as well. The game will also offer a change to the interface to make it easier to keep track of progress, by giving each character a mark that shows what boss they defeated last and on what difficulty. Hard mode will also alter the look of the game’s interface to make sure you always know what difficulty somebody is playing in.
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