Showcasing DE's history with experiments for increasing gameplay difficulty and rewarding gameplay that can be repeated: the so-called 'endgame'. Note that instances of power creep are undocumented since meta loadouts change constantly and there are so many to account for.
Update 7 - Stormbringer
Update 7.x Weapon Balance March 22nd, 2013 - First weapon balance sweep
Update 9.0 - Vor's Revenge
- Optional missions with increased enemy levels (by 10 levels) and gameplay modifiers.
- Can be accessed after completing all nodes of a planet.
- Rewards Nightmare Mode mods.
Update 10.0 - Shadows of the Dead
- Reward stacking in Survival missions and introduction to reward rotations (i.g. rotation A, B, and C) to this mission type.
- Mission/enemy level now determines what reward pool it will have, with higher-level missions supposedly drawing from a reward pool with better rewards.
Update 11.0 - Valkyr Unleashed
- Warframe armor buffs across the board so that no Warframe has base armor below 15.
Update 12.0 - Zephyr Rises
- Tougher versions of their normal counterparts with an aura buff/debuff to allies/Tenno.
Update 13.0 - Dark Sectors
- Clans can build Solar Rails to be deployed in Dark Sectors and apply a Credits tax to players playing those nodes.
Update 14.0 - The Mad Cephalon
Update 14.0 July 18th, 2014 - Enemy health uncapped
- All Infested enemies have behavior changes to increase the difficulty in fighting them.
- Player vs. player (PvP) game mode under the context of Clans battling over control over the Solar Rails of the Origin System.
- Borrows elements of Invasion system where players can side with a Clan to reap rewards.
Update 15.0 - Archwing
Update 15.0 October 24th, 2014 - Removal of Warframe Ability mods
Update 15.0 October 24th, 2014 - Defense and Interception stacking rewards
Update 15.5 November 27th, 2014 - Enemy Accuracy changes
Update 15.5 November 27th, 2014 - Infested faction expansion
Update 16.0 - Sanctuary
Update 16.0 March 19th, 2015 - Solar Rails discontinued
- The Law of Retribution was the first one.
- New Arcane Enhancement rewards.
- Can only be completed once per day.
- Max 8-player and min 4-player game mode.
- Player vs. player (PvP) game mode.
- Capture the flag, free-for-all, and team deathmatch.
- Exclusive rewards through Syndicate system.
- Warframes and weapons have modified stats to be 'balanced' within the game mode.
- Can only be equipped with PvP mods.
Update 17.0 - Echoes of the Sentient
- Second Trial mission with new Arcane rewards.
- Has Archwing gameplay tied into missions.
Update 18.0 - The Second Dream
- New system that revolves around Operators.
- Resource sink to convert wasted Affinity to Focus points to spend on upgrading Operator abilities, Warframes, or weapons.
- Series of three relatively high-level (levels 50-100) missions that each have a gameplay modifier.
- Reward after completing all three missions.
Update 18.5 March 4, 2016 - Warframe Ability Resistance and Immunity Changes for Bosses
Update 19.0 - (The Path To) The War Within
Update: Specters of the Rail July 8th, 2016 - Conclave rating removed
- Conclave rating was a numeric value that determines the 'power level' of a mod. A particular loadout can be arbitrarily restricted from being used in a special mission (e.g. Tactical Alerts) based on the conclave rating of the mods equipped on the Warframe and weapons.
Update 19.0 November 11th, 2016 - Endless Void Fissure Missions Changes & Additions
- Scaling rewards for Endless Void Fissures, including bonus Affinity, Credits, Resource, and Void Relic gain.
Update 19.0 November 11th, 2016 - Sortie Changes & Additions
- Riven Mods introduced into reward pool.
Update 20.0 - Octavia's Anthem
Update 21.0 - Chains of Harrow
Update 21.0 June 29th, 2017 - Dual-Wielding Thrown Melee And Secondary Weapon
- Buffs to thrown melee weapons across the board.
- Unique Grineer unit that has heavy damage reduction to bodyshots but headshots can only occur when helmet is broken.
Update 22.0 - Plains of Eidolon
- New avenue for obtaining Warframe Arcanes.
- Field bosses meant to be taken down by a squad.
- Repeatable until Plains of Eidolon is day time.
- New Focus nodes and changes to existing ones in the context of Operator mode introduced in Update 19.0.
- Increased caps on Focus acquisition.
Update 22.0 October 12th, 2017 - Weapon Falloff and Sniper Combo Changes
Update 22.12 February 9th, 2018 - Weapons Stat Rebalance
- Most primary and secondaries have been rebalanced based loosely around their Mastery Rank.
Hotfix 22.13.3 February 21st, 2018 - Beam Weapon Changes
- All beam weapons have been rebalanced based loosely around their Mastery Rank.
- Beam weapons can apply more than one status effect per second like other weapon classes.
- Damage ramp up added meaning beam weapons do not deal full damage until after a few hundred milliseconds.
- Beam weapons consume less ammo when being fired.
Update 22.14 March 1st, 2018 - Trials discontinued
- Endless game mode with arcade elements of killing enemies as fast as possible to progress.
- Normal and Elite versions with different starting enemy levels and rewards.
Update 22.20 May 17th, 2018 - Napalm and Rocket Bombard QoL Changes
Update 23.0 - The Sacrifice
- Special alert that is a high-level (starting level 60-80) endless mission with a reward rotation ABCCC... (C repeating, unlike the typical AABCAABC...).
- Unique gameplay modifiers like no revives, Warframe and weapon boons (buffs), and Arbitration Shield Drones that make nearby enemies invincible until destroyed.
- Game mode changes to make mission harder (such as lowering the percentage of life support restored upon picking up a life support capsule during Survival).
Update 24.0 - Fortuna
- Completing optional bonus objectives during Bounties reward extra standing and an extra reward from the reward pool if all stages have their bonus objectives completed.
- Enemy units on the Orb Vallis deal reduced damage.
Hotfix 24.0.10 November 21st, 2018 - New Elite Terra units on Orb Vallis
Update 26.0 - The Old Blood
- Experimental game mode to acquire Grendel's component blueprints.
- Player's Warframe and weapons will not benefit from mods with the exception of Warframe Augment Mods and Robotic Companion's precepts.
- Enemy level 40-45.
- Changes to Stances and improvement to flow of melee.
- Rebalancing of melees across the board based loosely around their Mastery Rank.
- Charged attacks reintroduced from Melee 1.0 in the form of heavy attacks that have scaling damage based on combo.
- New field boss that can use specific Warframe abilities.
Update 27.0 - Empyrean
- Ground enemies have higher base health than normal counterparts but are sparsely encountered, making them tanky as a result.
Update 27.1 February 4th, 2020 - Enemy Alertness changes
Update 27.2 March 5th, 2020 - WARFRAME Revised
- Introduction of Shield gating.
- Shields have an innate 25% damage reduction.
- Status Effect changes and rebalancing.
- Stacking procs have benefits.
- Over 100% status chance has meaning.
- Shotguns follow status chance calculations per pellet/bullet like other weapons (no more 100% status chance before multishot shenanigans).
- Shotguns status chance per pellet buffed as a result.
- Self-stagger introduced to replace self-damage.
- All AoE weapons have self-stagger if player is hit within the explosion.
- AoE weapons' explosion radii increased, but with damage falloff at edges of the explosion.
- Enemy Level Scaling changes.
- Enemy armor scaling nerfed significantly.
- Infested damage scaling increased.
- All armor, shield, and armor scaling curves have an S-shape instead of being exponential.
- For reference, at level 180, enemies will have about 3x less health, 3x less shields, and 2x less armor than before the update.
- Warframe armor buffs so that no Warframe has a base armor below 100.
- Enemy aimbot behavior reduced at higher levels.
- Grenade markers added and players now have the ability to destroy thrown enemy grenades.
- Larger variant of its Shield Lancer counterpart with a full-body sized impenetrable shield, making it only vulnerable to explosives or from behind.
- Features scaling rewards based on performance in Railjack and Ground Missions.
- Warframe Arcanes available through Scalet Spear credit shop.
- Changes to how healing and damage reduction abilities interact with defendable objects as seen here.
- Healing sources that scale based on objective's health nerfed to only heal to flat amounts.
Update 27.4 May 1st, 2020 - Railjack Revisited (Part 1)
- Enemy tankiness in Empyrean reduced across the board.
Update 28.0 - The Deadlock Protocol
- Features level 100+ enemies with 2.5x more armor, shields, and health.
- Resources and Mod drop chances doubled as a small bonus.
Update 29.0 - Heart of Deimos
Update 29.0 August 25, 2020 - Heart of Deimos
- New armored Infested units, Deimos Jugulus, Deimos Saxum, and Deimos Carnis.
- Immune to Viral procs.
- New ancient Infested unit, Deimos Therid.
- Shoots orbs of cobweb that can slow down the player.
- New field boss unit, Necramechs.
- Immune to status effects, has three small weak spots, and is able to make itself temporarily invulnerable.