OK, long post alert...
1. Grim Fandango Remastered also works in Windows (it's already marked as DRM-Free for Linux but ? for Windows).
2. Given their popularity, is it worth adding a link to Doom Classic and Heretic + Hexen games in the DOSBox section pointing towards the most popular source-port
GZDoom? This is by far how most people play them today and it adds a native Linux & Mac method. Currently it looks like you can't play them under Linux at all which is misleading.
3. I don't know if it's worth creating a separate section for this but there are a lot of ScummVM compatible games either missing or are marked as ? for one platform but not another, that I think you can safely add as DRM-Free for both Windows & Linux simply because ScummVM accesses the data files directly completely bypassing any included .EXE's (including any potential Steamworks / CEG). Eg:-
- Big Thinkers First Grade
- Big Thinkers Kindergarten
- Fatty Bear's Birthday Surprise
- Freddi Fish 1: The Case of the Missing Kelp Seeds
- Freddi Fish 2: The Case of the Haunted Schoolhouse
- Freddi Fish 3: The Case of the Stolen Conch Shell
- Freddi Fish 4: The Case of the Hogfish Rustlers of Briny Gulch
- Freddi Fish 5: The Case of the Creature of Coral Cove
- I Have No Mouse And I Must Scream
- Indiana Jones & The Last Crusade
- Indiana Jones & The Fate of Atlantis
- Inherit the Earth: Quest for the Orb
- King's Quest Collection
- Leisure Suit Larry 1, 2, 3, 5, 6 & 7
- Let's Explore the Airport with Buzzy
- Let's Explore the Farm with Buzzy
- Let's Explore the Jungle with Buzzy
- Loom
- Myst: Masterpiece Edition
- Pajama Sam 1: No Need to Hide When It's Dark Outside
- Pajama Sam 2: Thunder and Lightning Aren't so Frightening
- Pajama Sam 3: You Are What You Eat From Your Head to Your Feet
- Pajama Sam's Lost & Found
- Phantasmagoria
- Phantasmagoria 2
- Police Quest Collection
- Putt-Putt & Fatty Bear's Activity Pack
- Putt-Putt and Pep's Balloon-O-Rama
- Putt-Putt and Pep's Dog on a Stick
- Putt-Putt Enters the Race
- Putt-Putt Goes to the Moon
- Putt-Putt Joins the Circus
- Putt-Putt Joins the Parade
- Putt-Putt Saves the Zoo
- Putt-Putt Travels Through Time
- Return To Zork
- Rex Nebular and the Cosmic Gender Bender
- Riven: The Sequel to Myst
- Sam & Max Hit The Road
- Space Quest Collection
- SPY Fox 1: Dry Cereal
- SPY Fox 2: Some Assembly Required
- SPY Fox 3: Operation Ozone
- SPY Fox in Cheese Chase
- SPY Fox in Hold the Mustard
- Starship Titanic
- The Dig
- The Journeyman Project 1 Pegasus Prime
- Toonstruck
- Zak McKracken and the Alien Mindbenders
- Zork: Grand Inquisitor
- Zork Nemesis: The Forbidden Lands
All these games on Steam should play DRM-Free under both Windows & Linux under ScummVM. The list of actual data-files required per game can be found here:-
https://wiki.scummvm.org/index.php/Datafiles https://www.scummvm.org/compatibility/
Some of these games are already listed but misleading. Eg, Kings & Space Quest Collections are under "DOSBox" section as "Windows but n/a for Linux". However, if they run under ScummVM for Linux (without WINE) then they clearly are Linux compatible (which is something you've already done for Leisure Suit Larry 1-7 games in the general section).