Front right, there is a flower you can manipulate with Time (e.g. Doctor Strange). Use Time so the flower grows. The Minikit will appear above it.
Now, use Time again so the flower completely shrinks. A dig site will appear. Use it (e.g. Black Panther) to dig up Minikit pieces. Put them together.
There's a big fire standing on a silver lego frame. Blow it with Silver Lego Blowup (e.g. Ironman). Then extinguish the fire with Shield (Captain America). Destroy the remnants and put together the Minikit
In the arena, open 5 flags with Telekinesis (e.g. Doctor Strange)
Character in peril (Stan Lee)
Stan Lee is attacked by thugs near one of the flags for previous Minikit. Beat them to help him.
Find and shoot 5 Silver Statues with Silver Lego Blowup (e.g. Ironman)
At the spectator row in the back there is a big burger. Use Telekinesis on it (e.g. Doctor Strange). Then throw a Gravity Mine (Star-Lord) to get the Minikit.
Also in the spectator row, there is an Electricity Pad. Use Electricity on it (e.g. Thor). The Minikit will fall into the arena
Token: Beta-Ray Bill
Nearby there is a tracking spot (e.g. Black Panther). Follow the trace and dig out parts for a rake. Build it and use it with Telekinesis (e.g. Doctor Strange). It will reveal a pad for a Sphere (e.g. Ms. Marvel). Use it and remove the spikes so you can get the token.
Nearby there is already a place where you can use Double Rope Handle Pull (e.g. Spiderman)
Fly up to where the Red King sits. Behind him is a gold chained box. Use heat on it (e.g. Ironman)
Continue with the story until you have to throw a shield (Captain America) to the left to open a gate. A guy with a cart is coming out. Go inside where he came from to pick up the Minikit.