So steam is your best bet for gaming on linux overwll. For specific games:

Stellaris - space empire game, grow and manage your fledgling galactic empire with a large amount of flavour to change playthru to playthru. From being peace loving spacegoats to horrible all consuming bugs, its up to you.

Civilization series - similar idea to Stellaris but taking control of various famous world leaders to grow a nation state

Rimworld - its the Sims but you can commit warcrimes. Colony management game. Take control of 1 - 5 ‘pawns’ and try to survive in the harsh wilderness as long as you can

Factorio - build a factory. start as one person with a pickax and slowly build things to automate things so you can automate more things. The factory MUST grow.

Terraria - sandbox side scrolling adventure game. Hunt down monsters, ore and loot to craft better weapons and armor. invite local townsfolk into your well crafted box huts and create a little village

Counter strike 2 - premier clicking heads simulator. Very competitive fps game but even if your new just play a little death match to get used to shooting and moving, then jump right into competative. Tons of idiots but dw about toxic fucks. Mute them and have fun shooting people

Old school runescape - sandbox mmorpg. Start as a useless nobody, level skills by clicking till you have carpel tunnel syndrome and wonder where the last 1000hrs of your life went.

Kenshi - sandbox RTS/RPG game. Wander the desert, get attacked by a wandering pack of dogs and get patched up and captured by wandering slavers. Attempt a dramatic escape and lose an arm. Steal a prosthetic robot arm and run for the hills. Gather some followers and start a base. Then liberate the slaves from the slave colony you used to belong to

Deadcells - action side scrolling roguelike. You get one life to attempt to slay the hand of the king. 100s of different weapons and layout changes each attempt. Use a frying pan to smack the shit outta baddies or a giant broadsword to cleave them in half

Stardew valley - comfy relaxing farming Sim. take over your grandfather’s neglected farm. Grow crops, raise animals and become friends with the local towns folk. Argue with the broader stardew community about who the best person to marry is

Portal 1/2 - certified classic puzzle games. Shoot portals, solve puzzle and make the machine intelligence progressively angrier

Half life 1/2 - classic fps games that set the stage for storytelling in modern fps game. Recommend black mesa for HL1 over the og version

BioShock 1 - fps storytelling at its arguably peak form. Would you kindly play this game?

Disco elysium - unorthodox RPG game. Solve a murder mystery as a cop with no memory. Actually a novel in disguise with fantastic voice acting

Metro 2033/34 - another contender for fps storytelling at its finest. Can you save the people from the menace plaguing the Moscow metro stations?

Minecraft - THE sandbox survival game. Dig some tunnels, build a castle. Slay hordes of zombies, farm some pigs and wheat. Its been popular for a decade+ for good reason.

Dota2 - I dont play this myself but you said addictive and plenty of people have dumped 1000s of hours into this game. I’d say league of legends but that requires more effort to play on linux

All I can think of rn, besides dota all of these games have eaten 100+ hrs of my life at some point or another. These titles broadly cover my own taste in video games so I hope you find 1 or 2 to your own liking