Combat Encounter Rewards

After completing a combat encounter, you can either go through a Implant door, or you can pick one of a few randomly selected door types, you can see the door types listed below. Every other combat encounter has only a Implant door as an option (always having that as the choice for the first combat encounter of a biome), otherwise it's 2-3 randomly selected door types, excluding implant doors, and then the biome's Boss after a set amount of combat encounters specific to each biome:

Tora has 9 combat encounters before Torantula, leading to 4 Implant doors, and 4 randomly selected doors.

Watts has 8 combat encounters before Phoenix Apex, leading to 4 Implant doors, and 3 randomly selected doors.

Interport has 6 combat encounters before Iskra, leading to 3 Implant doors, and 2 randomly selected doors.
Interport is also the only biome that has Next Area doors that don't actually give anything, but instead just continue the combat encounter in a different arena. There can be multiple Next Area doors in a row before giving a reward and that combat encounter being considered complete.

Femto is a complete exception to how rewards work at the end of a combat encounter. In Femto, you select in the elevator's control panel one of 5 different rewards you want to for, and upon completing that combat encounter, you receive the reward. The 5 rewards available are randomly generated, with implants not even guaranteed like usual, except for the ??? reward that unlocks the Juggernaut Combat Shell. Upon completing at least one combat encounter you are able to choose to go to the final boss Lizz Watson, but for each combat encounter not completed, she has an additional 20% health.

If you want to learn more about what each upgrade does, see their respective linked pages to see more details.

Upgrades

Implant

This door is the only door generated not-randomly, and gives the choice between two new randomly selected Implants, or if the player has an implant that is able to be leveled up, upgrading one of your randomly selected implants you already have is a third option.

Neuralboost

This door gives a Neuralboost Upgrade, upgrading basic stats like maximum shield, health, defense, etc., and gives the choice between 2 common type Neuralboosts, and 1 rare type Neuralboost.

Shell Upgrade

This door lets you pick one of the class-specific Combat Shell Upgrades.

Weapon Mod

This door has class-specific Weapon Mods, including elemental effects, different weapon functionality (like 3 round burst for the Engineer's Gauss Rifle), and increased stats (increased reload speed, ammo capacity, etc).

Heavy Weapon

This door allows you to either replace your current heavy weapon with a randomly selected heavy weapon & heavy weapon mod, with two options to choose from, or you can upgrade your current heavy weapon. All three choices will leave the player with a heavy weapon one level higher.

Other Choices

Challenge

When opened it gives you an Implant immediately, but the next combat encounter is replaced with a challenge room which has one of that biome's Miniboss, and an endless supply of minions. If you have the 'Risk Reward' Implant, a randomly selected Implant is upgraded by one level upon completing a challenge room.

Shop

The door itself gives nothing when opened, but instead there is a Shop.

Credits

Upon opening, you are rewarded with 100 credits on VR-Orientation, 150 credits on Deep Dive, and 200 credits on Neuromancy.

Tokens

Upon opening, you are rewarded with 1 Token on VR-Orientation & Deep Dive, 2 Tokens on Neuromancy.

XP

Upon opening, you are rewarded with 250 XP on VR-Orientation and 350 XP on Deep Dive & Neuromancy.

Health

Upon opening, 50% of your health is restored on VR-Orientation & Deep Dive, 35% restored on Neuromancy.