The Steam Summer Sale continues and several games have been offered with big discounts. June 17 saw a 50 percent discount on a majority of "Final Fantasy" titles and a 75 percent discount on "Terraria." The sale continues along with its new monster mini-game and milestone system. 

The monster mini game is simple: Steam users have to play with other people in order to kill monsters in a short mini-game. This will help their team earn trading cards and craft badges. These are all needed to reach a milestone. With every new milestone achieved, the team unlocks new discounts for games. 

Some of the most recently unlocked deals include "King Arthur's Gold" which comes with a 75 percent discount and "One Way Heroics" which has an 80 percent discount. 

As of the time of writing, "Elder Scrolls V: Skyrim" is being offered for a 66 percent discount while "Metal Gear Solid V: Ground Zeroes" is available with a 75 percent discount. "South Park: The Stick of Truth" is available for a 66 percent discount, and TellTale's "Game of Thrones" game has a 50 percent discount. 

"Pillars of Eternity" currently enjoys a 33 percent discount. Those who have already gone through "Skyrim" can also avail of "Morrowind" and "Oblivion," previous entries in the "Elder Scrolls" franchise. 

"Bastion," "Mark of the Ninja," "Vampire: The Masquerade Bloodlines" and several "Tom Clancy" games are being offered for the June 18 flash sale as well. Their discounts range from 75 percent to 85 percent. 

The Steam Summer Sale will only last until June 21 and it is speculated by fans that some of the biggest sales and offers will be made on the very last day. However, because of the milestones needed to unlock certain deals, Steam users are recommended to start buying as soon as possible to unlock the best deals on June 21.