Browser based free games
Play free and free-to-play games designed to be played direclty in a browser (this includes both browser-based games and flash games)
Here are some of the best browser games you can play directly online: MMORPGs, collectible card games, strategy games and more. Browser games usually doesn't require nothing more than an updated browser (Chrome, Firefox, Edge, Opera, etc.) and are playable on any PC or Mac. Some of them may require a Flash plugin.
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Circus Hidden Objects
puzzle / hidden object
Zygomatic

Bit Heroes
RPG / MMORPG
Juppiomenz

Cut the Rope Time Travel
puzzle
ZeptoLab

FARA
RPG / roguelike
Brian Is Creative

Card Hunter
strategy / board game
Blue Manchu

atWar
strategy
atWar team

The Settlers Online
strategy / MMORTS
Blue Byte Software

Torn City
RPG / MMORPG
Joe Chedburn

Hattrick
simulation / management
Hattrick Limited

Daily Crossword
puzzle
zygomatic

8-Bit Bayonetta
action / run and gun
PlatinumGames

Imperia Online
strategy / MMORTS
Imperia Online Ltd.

Sextris
puzzle / tile-matching
Sextris

Progress Quest
RPG / idle clicker
Eric Fredricksen

Quick Fire Pool Instant
action
Miniclip

Tetris Fun
puzzle / tile-matching
zygomatic

There is no game
puzzle
Draw Me A Pixel

Travian: Legends
strategy / MMORTS
Travian Games

Strip poker online
card game / strip poker
net-assembly

Anno Online
strategy / MMORTS
Ubisoft Blue Byte

Battlestar Galactica Online
shooter / MMOFPS
Bigpoint Games