Marvel Super Hero Squad: The Infinity Gauntlet

For this achievement, you need to collect 100 Mind Fragments and smash Nightmare with 3 candles during one fight, both of which happen in the stage "Hulk have Nightmare".

After you've played through the stage in story mode, load up free play and select it again. While playing through in free play, make sure you smash EVERYTHING, even if you're sure you smashed it in story mode.

In the first room, you'll need to use an elemental hero to open a rift, inside are some Mind Fragments and a bouquet, also be sure to smash the grey pillars in this room.

In the second room, use Invisible Woman's ability at the energy portal to access the upper ledge and be sure to break the objest while you're up there.

After blowing up the building, use Falcon's speed ability to hit all the button on the raised ledge.

After placing the gear to open the door, be sure to smash all the green columns.

On the boss fight, after you beat Nightmare a little, he'll hop to the middle and place a bunch of bombs around himself. Using Hulk, run to one of the giant candles, press B and then use X to smash Nightmare. Do this 3 times and you'll complete the other required feat.

Once you're done with this level in free play, you should have enough fragments to unlock Hulk's feats and this achievement.