This version of Alexander is designed to be forgiving, so the mechanics aren't as perfectionist as Coil was when it first came out.

Now this is only my guess but for 1st stage, be prepared for 4 laser sights, 1 DPS grabbing each add and killing all 4 before the bombs touch down. That's one mechanic difference that might occur in the harder one on top of other mechanics they may throw in much like how Hard Mode and Extreme Mode tend to have new mechanics added on top of what they normally do.