Zero plays just like a classic Mega Man platform shooter. A jumps, B shoots, L dashes, and R and B together use the new secondary weapon. Zero not only has the traditional gun, but he also has a laser-sword.
I believe the biggest change to the series in Mega Man Zero is the much deeper plot. The title has in-game cut-scenes where much of the plot is revealed. It’s much more than the standard Mega Man X level where you just blast through and destroy the boss. From what I played at E3, Mega Man Zero looks to be an excellent addition to Capcom’s famous series.