Zealot difficulty is not that much harder than Normal difficulty. I'd highly reccommend playing through on Casual or Normal and starting Zealot on a new game+.I completed my Zealot playthrough 2 hours faster than my Normal one just because I knew what I was doing.Before you new game+ you can use the power node exploit (video at bottom) to fully upgrade your weapons, rig and stasis module and it will make Zealot a ton easier. Also having power nodes to open all the storage cupboards is always helpful.If you get stuck on a checkpoint try the stasis and run tactic. You may often find yourself with low health and/or with no ammo.

I've been watching a streamer play dead space 2 and remembered I actually got this achievement either the week or second week the game came out. Frozen in Time is an achievement in Dead Space 2. It is worth 10 points and can be received for: Kill 50 Necromorphs while they are in Stasis.

This method is extremely effective in certain levels although you're not going to be getting any ammo/health/credit drops so don't overuse it.Other than that it isn't that hard, the 4 weapons I used were Plasma Cutter, Pulse Rifle, Force Gun and the Line Gun.Plasma Cutter and the Pulse Rifle are good for general use. The Force Gun is good for areas where your in an enclosed space and the Line Gun is amazing for when you're getting over run.Other than that it's actually not as hard as you think.

Have fun.EDIT: Oh yea and beating the game on Hardcore won't unlock this achievement so you might aswell tackle this and get used to the game before you attempt Hardcore. Scram kitty dxf files.