Spider-Man: Shattered Dimensions

Spoiler Alert !!!!! A real easy place to get this achievement is in the fight against Mysterio. The first of the Four Spider-Man you play with is Noir Spider-Man. All you have to do in this section is make it to Mysterio. Just take your time and STAY in the shadows. Right after you climb the wall and grapple Mysterio and bash his face on the rock the achievement should pop. As long as you were never hit by him. He throws random fireballs out every once and awhile. Really nothing to worry about cause 95% of the time he shoots it in some random direction.

Also as stated by Spletchie(thank you) if you take damage, "Quit" to the menu and start the level over again - if you just use the "Restart" option to go back to the beginning of the level, the achievement won't pop.

All you have to do is get through the Noir portion of the Mysterio boss battle without being detected and it will pop. That's it.

Best done on the easy setting. Easy boss is Sandman in Act 2. Take advantage of the wide open arena. Throw water barrels at him with the B button to turn him to mud then get in close and strike. Hammer attacks are simple to dodge. Be aware he may create a giant hand or shoot sand in a circular motion. Rinse, wash, repeat for 20.

Believe it or not, Carnage on Hard is where I got this achievement.

Trick for the egg phase is to let the slayers do all the work of burning the egg. Just avoid the little carnage-lings. (They're sparser on the upper levels and easier to avoid in the brighter lighting.) The game will yell when a slayer falls but SHIELD HQ will send in more if they all fail.

Once Carnage comes out, follow the prompts to dodge Carnage's slashes in the face-to-face moments. And once out to third-person, hit him while he deals with the slayers that are left (there will always be one and he does this egg/burn/destroy cycle 3 times, so the corresponding Carnage destroy slayer challenge should be in the bag). Then dodge out of the way when he shields up. And run far away and keep running so that his subsequent chosen attack won't get you.

Here's the sweet spot. Carnage has a blind side. After his shield aftermath attack, he'll start running and if you run towards him head-on he'll immediately dodge out of the way and attack. BUT if you run off to the side, he often doesn't notice. Once you have a moment where you see him running past, rush him from that blind spot and you'll get some hits in before he again shields up. Rinse and repeat. Go through 2 more eggs like I mentioned above and you'll have Carnage down with no blood lost. ;)

Three tips:
Don't be scared if you're "found out" by Carnage before you get a hit in. Just dodge and run. Carnage himself usually dodges first before attacking you and he spots and reacts from a distance too. If he notices you when you're about to hit he's too late anyway, you'd have already pound him. ;)

Keep away from the center when you fight. That's where Carnage transforms into egg mode. It doesn't seem to hurt Spidey the one time I got caught in it but it is disorienting and I'd rather not take the chance.

Also don't zipline when Carnage is out! Only go to the upper levels for easier avoidance of carnage-lings. Staying on the ground is all that's needed for fighting Carnage himself. Ziplining to the upper levels leaves you vulnerable to Carnage's own zipline attacks. (Needing the Spider Emblems for health up there just means you have to start this achievement attempt over. ;) ) Stay on the ground!

Good luck!