Epic Games:

Second Extinction™ - Link

Big map. Big dinosaurs. Big guns. Face an ever changing threat level with your friends.
Second Extinction is an online co-op FPS with a bite.
You take on hordes of mutated dinosaurs with up to two friends.

Still in Early Access

Solo players beware: Second Extinction is designed with squads in mind. Only the strong will survive.


Ongoing and Free for a Longer Period
Cave Story Secret Santa


Next time: More Winter Holiday Mystery!~

[Microsoft]

Farming Simulator 16

[Xbox]
Ikaruga*

*You don't need to change the localization in the address bar or your IP location. Just simply be logged in and claim it.

Epic Games:

Mutant Year Zero: Road to Eden - Link

Mankind has been eradicated by climate change, nuclear war, and pandemics.
Will your team of mutants survive the Zone?
It is a tactical adventure game combining turn-based combat with real-time exploration, story, stealth, and strategy.

Repeat

Ongoing and Free for a Longer Period
Cave Story Secret Santa

Next time: More Winter Holiday Mystery!~

edited because that long sentence alignment bugged me

①  Cytus II؜, a rhythm-based game, is temporarily free on Google Play؜ (Android) and the App Store؜ (iOS).  The in-app purchases are optional and let you buy additional music and characters.  Here's a gameplay video؜.

②  Wojciech Wysocki is giving away ShapeOminoes؜, a puzzle game, on both Google Play؜ (Android) and the App Store؜ (iOS).  Here's a gameplay video؜.

③  Maciej Targoni, the developer of Hook and Klocki, is giving away two games on Google Play (Android) :

    ▪  oO؜     ( Arcade game  ∙  Gameplay؜ )
    ▪  Push؜     ( Puzzle game  ∙  Gameplay؜ )

④  The following games are free for a limited time on Google Play (Android) :

    ▪  Paranormal Territory؜     ( Survival horror  ∙  Gameplay؜ )
    ▪  Stone Of Souls HD؜     ( Survival horror  ∙  Gameplay؜ )
    ▪  SlingFighter؜     ( Fighting game  ∙  Gameplay؜ )
    ▪  Word Cage؜     ( Word game  ∙  Gameplay؜ )
    ▪  Broken Words؜     ( Word game  ∙  Gameplay؜ )
    ▪  Broken Sentences؜     ( Word game  ∙  Gameplay؜ )
    ▪  A Tale of Little Berry Forest 1: Stone of Magic؜     ( Adventure game  ∙  Gameplay؜ )
    ▪  Sudoku Pega؜     ( Puzzle game )
    ▪  Super Runner؜     ( Arcade game )

⑤  The following games are free for a limited time on the App Store (iOS) :

    ▪  Cubes: Brain Teaser؜     ( Puzzle game  ∙  Gameplay؜ )
    ▪  Helius: Full of Life؜     ( Puzzle game  ∙  Gameplay؜ )
    ▪  Trigono: Dangerous Triangles؜     ( Arcade game  ∙  Gameplay؜ )
    ▪  Gruffalo: Puzzles؜     ( Education  ∙  Gameplay؜ )
    ▪  Mr. Nussbaum: 46 Game Super App؜     ( Education )
    ▪  Color Tap: Coloring game؜     ( Casual game )

I Have No Mouth And I Must Scream is free on GOG:
https://www.gog.com/game/i_have_no_mouth_and_i_must_scream

Vampyr is free on Epic Games Store:
https://www.epicgames.com/store/en-US/p/vampyr

①  Mateusz Janczewski, the owner of Subpixels and the executive producer at Spokko, a member of the CD Projekt family, is giving away Sphaze؜, a sci-fi puzzle game, for the next two days on Google Play؜ (Android) and the App Store؜ (iOS).  The in-app purchases are for hints and solutions.  Here's a gameplay video؜.

②  B.D.R.S: Biological Disaster Response System؜ (full version), a simulation game about biological disasters, is currently free for the next two days on Google Play (Android).  Here's a gameplay video؜.

③  Space Borders: Alien Encounter؜, a real-time strategy game, is temporarily free on the App Store (iOS).  The in-app purchases let you buy an add-on (Conquest Mode).  Here's a gameplay video؜.

④  Peninsular War Battles؜, a turn-based strategy game also available on Steam؜, is temporarily free on the App Store (iOS).  The base game contains 16 missions, and 4 additional campaigns are offered as in-app purchases (8 missions per campaign).  Here's a gameplay video؜ of the mobile version.

⑤  The following games are free for a limited time on Google Play (Android) :

    ▪  Mayatch؜     ( Match 3 game  ∙  Gameplay؜ )
    ▪  Aero Effect؜     ( Arcade game  ∙  Gameplay؜ )
    ▪  Infinity Highway؜     ( Racing game  ∙  Gameplay؜ )
    ▪  The Dollar Game؜     ( Puzzle game  ∙  Gameplay؜ )
    ▪  Manor؜     ( Platformer  ∙  Gameplay؜ )
    ▪  Ego Rigo؜     ( Arcade game  ∙  Gameplay؜ )
    ▪  Quiz G؜     ( Trivia game )
    ▪  Classic Offline Sudoku؜     ( Puzzle game )

⑥  The following games are free for a limited time on the App Store (iOS) :

    ▪  Wordsmyth؜     ( Word game  ∙  Gameplay؜ )
    ▪  Rush Rover؜     ( Top-down shooter  ∙  Gameplay؜ )
    ▪  Spinny Monster؜     ( Arcade game  ∙  Gameplay؜ )
    ▪  A Tale of Little Berry Forest؜     ( Adventure game  ∙  Gameplay؜ )
    ▪  SuperMouse؜     ( Arcade game )

Epic Games:

Pathfinder: Kingmaker - Enhanced Plus Edition - Link

Pathfinder: Kingmaker - Enhanced Plus Edition is the first isometric party-based computer RPG set in the Pathfinder fantasy universe. Enjoy a classic RPG experience inspired by games like Baldur's Gate, Fallout 1 and 2 and Arcanum.

What does the "Enhanced Plus Edition" consist?
Besides the long vague list in the store page, content and more random encounters or what have you...
Enhanced Plus Edition is basically the base game with all major updates included (no DLC)
It is just a fancy name for updates after v2.1 update last year.
Given that all major platforms sell the most updated version of a game, it is what everyone receives now.
Unless you want the a version before v.2.1 for older mod compatibility, then you won't find it here.

DLC bonus:
Arcane Unleashed

Ongoing and Free for a Longer Period
Cave Story Secret Santa

Next time: More Winter Holiday Mystery!~

edited to fix grammar and added dlc that is always free

Hi! :)
One of the free DLCs is missing: Pathfinder: Kingmaker - Bloody Mess DLC

There is also another:

https://www.epicgames.com/store/en-US/p/pathfinder-kingmaker--arcane-unleashed

Green Man Gaming have a free random game giveaway to Bronze level members and above. Higher level = better game, or even store credit.

Thank you for catching my oversight!

BIG happy holidays greeting to everyone on this special day!!
May you all get tons of presents and stay safe and healthy!

And Epic also has a nice present for us today too!


Epic Games:

Prey - Link

One of my favourite games of all time!
Prey is a FPS and action-adventure game. You are Morgan Yu (can choose female or male in-game).
You awaken aboard Talos I, a space station orbiting the moon in the year 2032.
You and your brother are operating a company equivalent to NASA in real life.
You go through a series of tests only for something to go awry.
The alien specimens in the experimental lab rebel and attack everyone!
What will you do? Which side would you choose? Fate of humanity rests in your hands...or gloo cannon.

Side note: There are also fun Easter eggs and special secret games inside the game.
Highly recommended for RPG and board game lovers to explore those side missions!
Take your time and explore everything to get the most out of this game and the mystery behind Talos I.

Ongoing and Free for a Longer Period
Cave Story Secret Santa

Next time: More Winter Holiday Mystery!~

Note that the Mooncrash DLC is also included !

Epic games does free game every 24 hours during Christmas time