There is plenty of free games out there. And in so many genres. Most of these games add in-game purchases, some of which tip the balance of power. But this list will not contain such games.
These 5 action games, in no particular order, deliver quality, fairness and hours upon days upon months or more of fun.
Please note, that there aren't any MMORPG, MOBA's and CCG's, since there are so many, they deserve their own list.
And the first title is sort of a cheat, sorta. Alien Swarm: Reactive Drop is an expansion/ newer version of Alien Swarm. A top-down, 4 to 8 player co-op game, where you and your squad take on missions to get rid of, well swarm of aliens. Reactive Drop adds new maps, weapons, aliens, bots, and steam workshop support. Though still in beta, the game is entirely free. The only negative about the game is that friendly fire is on, so be careful when playing with randoms.
In my opinion, no list like can skip over this legacy game. Ten years going, and still, the now small dev team are focusing on new modes, maps and constantly fixing and balancing.
Among other things, its Free To Play model, not only is the base for plenty of others and it has gotten better. As of writing this, there is nothing but cosmetics in the store, any weapon can be crafted or dropped or rented from the store. And yes, free accounts have some restrictions on them, like no trading, gifting, or special crafting. But. all it takes a single purchase from the Mann Co. store (the cheapest thing being 90 cents for a map stamp) and you get upgraded to premium status instantly. Not only that, but special events like Halloween and Christmas give free premium items.
Take a Diablo game, give it so many upgrades and skill customization options, it will make your head spin, a constantly evolving story and make it free. That is Path of Exile. Fun and addicting hack slash, with constant new content being added, balancing on the regular. And a business model focused entirely on cosmetics and bank tabs, nothing remotely to impact gameplay.
Here is a title that gives so much for nothing, that its baffling how it keeps on going. A solar system of missions, PvP modes, flying missions and even an open world portion. Couple that with great graphics, tons of weapons and mods, many different classes, and generally balanced gameplay, Warframe could well be a paid game and no one will mine. And yet, the game is free only striving on cosmetics, boosters and the “Prime Access” system which is just getting the new things instantly without crafting them.
Can't make a list of “Great Free Games” and leave out the most popular one currently. Originally, Fortnite was a paid zombie hard game, Epic saw the potential of the new “Battle Royal” genre game, popularized by PUBG(Player Unknown's BattleGrounds). So they took the base game of Fortnite and made Battle Royal mode, gave it free with a cosmetic and emote shop to make income and done. Now anyone can play against 99 people on an island, relying only on their skill and chance to be the last one alive. Happy hunting.