Gameplay
Full description, guide and gameplay of this deck can be found in the video.
Ideally you want to use Adam Warlock and Ebony Maw on T3 to get extra cards flowing.
Use Electro / Psylocke / Wave (in order of preference) to enable Galactus on T5.
T6 use Gamora and Death with Demon if possible, or Rocket for a little boost.
Demon and Rocket are both safe from Chang-Chi, so keep that in mind as they're sometimes the best option if you can see him coming.
Brood is there to populate the board and reduce the cost of Death when Galactus is played.
Replacements:
Uatu is the least important card here, it's nice to know which locations you have to work with early on, but by no means essential. Replace him with a Killmonger to combat awkward locations like Central Park, or Ninja Town (whatever it's called). He's also good when you've played on Turn 1 and need to clear the space again because the locations have worked against you.
If you've got Knull, get him in. Replace Uatu or Brood. With Knull you can drop your Demon early as his power is picked up by Knull. He also makes a T4 galactus more viable as you aren't worried about your Gamora / Death being Shang-Chi'd.
Snapping
In lower ranks (sub 50) you can confidently Snap on T4 if you have the required cards in Hand. Your biggest T5 threats are Cosmo and Aero, if your opponent snaps after T4 check the turn priority - they probably see what you're doing.
Remember
If your opponent plays Shuri, but the following card is destroyed before it gets revealed, then the next card they play will receive the buff from Shuri.
If you're running Knull, he will receive the power of cards destroyed before they are revealed.