Buildings
Make sure you buy buildings whenever you can as they will earn you money over time and also enable you to take on Contracts for big rewards.
Icons
Always keep an eye out for brightly coloured icons above buildings as this indicates it can be used to take on missions or Contracts. If the icon above the building is greyed out the building is not yet ready.
Upgrade HQ
It is important that you regularly upgrade the HQ so that you increase the maximum level you can upgrade everything else to.
Gold Bags
Keep an eye on the map for glowing bags and tap on them to to collect the Gold within.
Free Rewards
Every few hours you will be able to claim free rewards which you can deposit in your Liberty bank. Just make sure your Liberty bank is able to handle the extra resources otherwise you need to make upgrading it your prime objective.
R&D Facility
Make sure you check in to your R&D facility every now and then so you can claim your money and free rewards.
Replay Missions
Once players reach floor 8 in a mission they will able to unlock a reward box to get a prize. There are about fifteen boxes to choose from but players can only select one. To unlock all the reward boxes and get all of the high reward cards, XP, and proton pack parts that are inside players can replay the same mission multiple times until they have unlocked all the boxes.
Reloading Proton Packs
Keep an eye on your ammo because although Proton Packs reload automatically when they are empty the process of them replenishing will leave you defenseless in the meantime. Get into the habit of manually reloading by pressing the reload button on your proton pack.