Good games for a low end PC

Stardew Valley (relaxing, farming),
Pony Island (funny),
Antichamber (original puzzle),
Call of Juarez, Call of Juarez Gunslinger (shooters, story),
Deus Ex, Deus Ex: HR (stealth, story),
Mafia I, Mafia II, (story)
Portal, Portal 2 (original puzzle),
Dishonored (stealth),
Europa Universalis IV (strategy),
The Talos Principle (puzzle),
Grim Dawn (diablo),
Darksiders, Darksiders II (parkour-ish hack'n'slash),
Epistory (isometric typing game, cute),
Banished (strategy),
Hue (original puzzle platformer),
The Wolf Among Us (story, interactive movie),
Dead Synchronicity (point & click, story),
The Last Door (point & click, story, pixel art, horror-ish),
Mini Metro (strategy),
Sunless Sea (slow exploration, story),
CHUCHEL (CHUCHEL).

From the stuff in your Library:
You have Psychonauts and haven't played it so I'd definitely recommend that one.
People tend to praise Amnesia: The Dark Descent and I'm pretty sure it has low requirements.
Similarly Brothers - A Tale of Two Sons though I personally wouldn't recommend that one since it's cripplingly depressing.
One Finger Death Punch is great and it's one of those "games you can play basically for as long as you like" since it's practically endless. :D

From stuff that you don't have:
Half-Life 2 and its episodes are great games and can probably run on a toaster.
Same for Portal 1 and 2.
Terraria is also a very good game and if you end up liking it could cut quite a while of that 10 month wait. XD
Similarly FTL: Faster Than Light.

There's a laaaaarge variety of games that don't require a crazy computer. Maybe narrow it down a bit by saying what genres you're looking for in particular? ^_^'

i don't know if you played these yet:

darkest dungeon
dead in bermuda
deponia
invisible inc
pillars of eternity
xcom

telltale games

Bastion, Owlboy, wolfenstien

GTA Trilogy :0

Transistor, Banner Saga, Super Meat Boy, Fez, Limbo, Inside, Into the Breach, Salt and Sanctuary, Shank, Guacamelee, Shantae, Shovel Knight, Undertale, Skulls of the Shogun, Valdis Story, Oxenfree, Binding of Isaac, Braid, Deadlight, Mark of the Ninja, Don't Starve, Bionic Commando Rearmed, Child of Light, Valiant Hearts, Might and Magic: Clash of Heroes, OlliOlli, The Swapper, Outland, Pony Island, Papers Please, Dankest Dungeon

im playing stick fight: the game with my old macbook. (I just play it myselt as single player game... not differences as far as you have internet)

Broken Sword's, any CAVE game, Aliens vs Predator 2, American McGee's Alice, Worms Armageddon, The Witness, VVVVVV, Vampire - Bloodlines, Unreal Tournament 2004, Thief 1-2-3, Super Hexagon, Jedi Knight 2: Jedi Outcast, Jedi Knight: Jedi Academy, The Stanley Parable, Civilization 3, Serious Sam 1-2, any kind of Visual Novels, Quake 2, Quake 3 Arena, Quake 4, Prince of Persia Trilogy, PAC-MAN™ Championship Edition DX, Orwell, Metal Slug's, Max Payne 1-2, Mafia, King's Quest, Jets'n'Guns GOLD, Hotline Miami 1-2...

1990s era first person shooters are a favorite of mine. Doom/Doom 2, Heretec, Hexen, Strife: Quest for the Sigil, Quake, Malice for Quake, Descent, Descent 2, Shogo: Mobile Armor Division, Eradicator...

Older Bethesda games: Morrowind, Oblivion, Fallout 3 , Fallout New Vegas. These games were practically my childhood.

mount&blade warband, its awesome and runs on potato too.

Since I don't know which genre you prefer, here's a mixture:

• Dead Space 1-2 (sci-fi horror TPS with a good story and an amazing atmosphere)
• the original Unreal Gold (was free a few months ago, one of the best FPS ever made)
• Baldur's Gate 1-2 (the best RPG ever)
• Amnesia (great horror with an outstanding story)
• Fallout 1-2 (post-nuclear turn-based RPG)
• The Witcher: Enhanced Edition (another great RPG with a unique fantasy world)
• Thief 1-2 (the best stealth FPS ever made)
• Call of Juarez (a very good western themed FPS)
• Arx Fatalis (RPG-FPS underground)
• Resident Evil 4 (one of the best of the series)
• the original Deus Ex (amazing sci-fi FPS)

TowerFall! :D
Roller Coaster Tycoon! (The original! :D)

Mount and Blade Warband
Bioshock
Brutal Legend
Alan Wake
Amnesia Dark Descent
Both Penumbras
Guacamelee
The Binding of Isaac
Fable Anniversary
Zeno Clash
Gothic 1-3

https://www.steamgifts.com/discussion/TpRDr/modern-games-that-run-on-a-potato-machine-small-gib-added-level-1-basic-sg-ended
Hope this helps

Lucasarts adventures
Sam & max (all of the games) Point & Click- Adventure- funny
Chronicles of Mystery: The Scorpio Ritual (Point & Click Adventure)
Jack Keane (Point & Click Adventure)
Jack Keane 2 - The Fire Within (Point & Click Adventure)
Broken sword (all of the games) Point & Click- Adventure
All these will run on a older pc 😊 👍

You could check a few games at https://www.systemrequirementslab.com/cyri to see.

Happy cake!

Here are my recommendations, but you still have to check the system requirements
https://store.steampowered.com/app/464360/3030_Deathwar_Redux__A_Space_Odyssey/ Processor: 1 GHz, Memory: 1 GB RAM
https://store.steampowered.com/app/6090/Armed_and_Dangerous/ Old, but gold
https://store.steampowered.com/app/434240/Alien_Blitz/ top-down shooter
https://store.steampowered.com/app/289890/762_High_Calibre/ Tactical, RPG, Action, Strategy
https://store.steampowered.com/app/37100/Aztaka/ side-scroller action Memory: 2 GB of available system memory
Graphics: 256 MB (512 MB recommended)
https://store.steampowered.com/app/259490/Beast_Boxing_Turbo/ Minimum:OS: XP or greater Probably will run on calculator
https://store.steampowered.com/app/302710/BlazeRush/ Racing game Memory: 2 GB RAM
Graphics: 512 MB recommended System Requirements
https://store.steampowered.com/app/270110/Block_Story/
https://store.steampowered.com/app/15270/Cold_Fear/ Survival horror
https://store.steampowered.com/app/4720/Condemned_Criminal_Origins/ Psychological Horror, FPS
https://store.steampowered.com/app/2100/Dark_Messiah_of_Might__Magic/ Highly recommended game from Arkane studois AMD Athlon™, Pentium® 3.0 GHz, 256mb dx9 video card
https://store.steampowered.com/app/39200/Dungeon_Siege_II/ Classic Action RPG
https://store.steampowered.com/app/293440/Elliot_Quest/ Metroidvania
https://store.steampowered.com/app/404410/Endless_Sky/ IT'S FREE
https://store.steampowered.com/app/21090/FEAR/ One of the best FPS ever made
https://store.steampowered.com/app/392100/Fatal_Theory/ Fun little beat 'em up Memory: 1 GB RAM Graphics: Any
https://store.steampowered.com/app/214970/Intrusion_2/ Fantastic side-scrolling shooter
https://store.steampowered.com/app/8190/Just_Cause_2/ Cause why not
https://store.steampowered.com/app/219830/King_Arthurs_Gold/
https://store.steampowered.com/app/284180/Magicians__Looters/ Another metroidvania
https://store.steampowered.com/app/260190/Marc_Ecks_Getting_Up_Contents_Under_Pressure/ Conspiracy, graffiti, parkour, amazing soundtrack, third person, stealth
https://store.steampowered.com/app/40380/naild/ Amazing racing game

Fallout 3 GOTY
The Saboteur
CS: GO
Portal
Mafia II

Championship Manager 01 / 02

https://www.fmscout.com/a-championship-manager-0102-free-download.html

what comes to mind right now : black and white 1 and 2
bloodrayne 1 and 2 (and maybe bloodrayne betrayal too )
age of empires hd

happy cake day :D

saint row franshise

Banner Saga series.
Invisible Inc.

This amazing game
https://store.steampowered.com/app/264200/One_Finger_Death_Punch/