On the original Flash version (most common in unblocked 76), sacrificing health on spikes can teleport you to the Angel Room or Devil Room early. It’s a gamble, but high-quality versions process the teleport instantly.
The Binding of Isaac (especially Rebirth and later expansions) is not a browser game. The original 2011 Binding of Isaac was built in Flash, which is now defunct (Adobe killed Flash in 2020). Any site promising "The Binding of Isaac Unblocked 76" is likely one of three things: the binding of isaac unblocked 76 high quality