With the lowered enemy count they increased enemy health and made it much harder to delimb enemies. Some other things about Sigma 2
-Incendiary Shuriken Ninja no long throw IS but instead drop slow bombs at you
-Enemy grab attacks are slower but deal much higher damage
-The bow has a terrible lock on and no UT but now allows you to move whilst aiming which is really nice.
-You don't get to use IS or the Windmill Shuriken
-One boss was removed and another was replaced. Both in Ch.09.
-A couple new ones were added and they're bad, one right after you fight what was previously the chapter end boss
-Plus there are 6 chapters where you play as the series' girls which you may or may not like. I only liked Ayane's stages personally. You can't skip them and they're thrown in in between middle stages.
-Oh, you also get the VF in Ch.03 as opposed to Ch.09 and there's a new weapon.
It also has horrible loading times. Like in NG2 in the first couple chapters you pick up a tutorial scroll and get a video which you can immediately cancel out of. On the PS3 you have to wait what feels like an eternity for it to load up to cancel out. Or just ignore the scrolls after the first time, provided you remember which items those were.
Ready to die? A Compulsory Happiness Dictatorship. ''Alrighty~ Come on everyone, you should only be full of happiness!''
Uh, Gardevoir? http://imgur.com/bANy38Z