The Wizard is stuck in his balloon that was attacked by the tree it is now caught in, and can't get down. In order to reach him, you first must trap the ghost swarm with Peter Venkman and the Ghost Trap. You can also use Abby Yates. Once you do this you only have to use the Laser Ability to break open the golden basket and free the wizard.
Clara is on the first stage trapped in what appears to be a capsule. To save her, you first need a character with Fix-It Ability to fix a computer, once this is done you need a character with Boomerang Ability to open the capsule and free her.
Clara is on the first stage of the level on an out of control horse (a reference to Back to the Future III). To save her, you need a character or vehicle with Growth Ability to grow a gigantic carrot in order to calm down the horse.
Dana is trapped in a room on the Titanic (bonus area). To save her you need to travel to the 1912 Titanic and use a character or vehicle with Grow Ability to grow a plant. When you return to the present the giant plant will free Dana.
To save her, you need a character with Master Build Ability to build Shaquille O'Neal's catapult and use a character with Magic Ability to load it with a snail. You must throw it to a tower and she will descend from it. (A Dalek will also be destroyed)
On the Destiny Bounty, (secret area) he is on the anchor. You need to pull a handle to pull the anchor, however, you will be attacked by Robot SWATs and the handle will be destroyed. After you defeat them, use a character with Grapple Ability to finish pull the anchor and save Jacob.
Ralph is stranded on a raft in the sea near the shore. To get him back on land, you need Aquaman's Atlantis Elemental Ability to summon a giant water brick-built Seahorse that will dive into the water, therfore returning Ralph to shore.
Judoon is trapped inside of a vine-like cage in the apocalyptic version of London which requires the Vine Cut Ability to free him. You will then need to follow him over to another area and use the Grapple Ability to reveal a teleporter which will bring him to safety.
To save him, you need to go to the right side of the CIA Headquarters and use a character with the Drill Ability to drill into a wall to reveal an IMF Disguise Scanner. Use Ethan Hunt to perform his Scan Disguise Ability to disguise as a security guard to disable some lasers and you will see Benji trapped on a bomb. Use a character with the Magic Ability to send a pair of pliers to free him.