Everspace is a Space-sim Rougelike thingamabob, comparable to FTL, but with much more focus on the actual flying and dogfighting aspect rather than just ship management, although ship management is still very important otherwise you're gonna be dying a ton. The Mouse & KB Controls are Gorgeous and so well optimised for this type of game.
As this is a Rougelike, be prepared to die a ton, thats just the nature of the game, as well as the procedually generated nodes in each sector, the first 2 sectors are pretty bland at times, but theres always some action going on. The Recently released Encounters DLC Adds a new ship called the Sentinel, equipped with mean ass Corrosion Missles and Lightning Guns, it also (surprise, surprise) adds new encounters and more things for you to do during your runs, for the all important credits. Credits are how you buy upgrades to your ships, yes, the upgrades are seperate for each ship, talking of ships, the ships in the game are:
The Interceptor - Medium Fighter - All Round Good starter ship
The Scout - Light Fighter - Fragile but very nimble - Can equip cloaking devices
The Gunship - Heavy Fighter - Huge Hull HP but very clunky - Has No Shielding and is not equipable
The Sentinel - Medium Fighter - Faster Hacking and Extra Slots - EMP is best Getaway device
Assetto Corsa is a Racering Simulator, you do racering in it and shit, it is very moddable and has many different "Apps" as the game calls them to extend the funtionality of the game, with new widgets for in game, my personal favs being SideKick and HeliCorsa, which give you a very nice HUD and spacial awareness of cars around you.
AC has around 44 cars in the base game, with 107 cars across the current set of DLC and 9 new tracks across the DLC's giving tons to do with just the official content, the game's replayability of course comes in mods, new cars, tracks and apps can all be made as mod content for the game, allowing people to extend and make Assetto Corsa their go-to Simulator, which fall into Kunos' slogan for the game "Your Racing Simulator"
If you are looking for mods for this game, The Race Department is your best bet for high quality and well made free mods, but there are also paid mods too, most of them i advise to stay away from, but Race Sim Studio is the exception to that, their quality and overall feel of their products in the game are second to none and cant reccomend them enough, seriously.
Warframe, your local Space Ninja Simulator and home of SpaceMom, the best Mom. Warframe is a game about having a huge ass power fantasy while jumping around doing sick flips and running along walls while shooting a bow that slows enemies and then the bolts explode, its one of those games, its also a f2p, wait, come back, let me explain.
Digital Extremes, the guys who made the game, have done tons, and i mean tons, of work to make sure those that dont spend money on the game are just as powerful as those who do. The main focus of the game is the PvE element, the Conclave is pretty fucking dead, no one cares for it anyway to be honest, its just there. recently Plains of Eidolon (PoE) dropped and added a free roam MMO area to the game, with random events, pillageable Dargyns, Fightable Eidolons at night, flying around with your Archwing, and the best part, Fishing!
Terraria has a rep for being the 2D minecraft, but is so much more than that. Terraria is a 2D sandbox with many bosses, NPC's and different blocks and items to craft and use, as well as vanity items such as dyes and mounts, it is a much more full featured minecraft in a sense, with many hours of play before you reach hardmode, or even endgame!
The game in its current state is massive, with mods and tons of other bits to play with, terraria is deffo worth it if you cant afford the £18 for Minecraft.