Single-player games like Harmonia
Below are 14 single-player Steam games similar to Harmonia, ranked by player overlap. Every pick carries Steam's Single-player category, so multiplayer-only titles or always-online games don't sneak in. imho.run pulls the category data from Steam directly — Single-player here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Harmonia page.
Ranked picks
- 1

planetarian HD
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Simulation with Harmonia.
planetarian HD is an engaging and emotional visual novel from legendary game studio, Key. A sub-brand of VISUAL ARTS, Key are also famed for creating Kanon, AIR, CLANNAD, Little Busters!, Rewrite, Angel Beats!, and Summer Pockets.
- 2

Stella of The End
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Simulation with Harmonia.
Jude Gray, a wandering Courier, receives a request to deliver some very special cargo. This cargo turns out to be Philia, an android girl who is unaffected by the enigmatic Singularity Machines.
- 3

Stellaren II
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Simulation and Casual with Harmonia.
A space sci-fi visual novel in post-apocalyptic worldCombines a unique visual novel experience with multiple mini-games!Travel across multiple locations across space and meet a diverse set of interesting characters.
- 4

planetarian ~the reverie of a little planet~
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Casual with Harmonia.
In time for the 10th anniversary since its original release in Japan, planetarian is an engaging and emotional visual novel from legendary game studio, Key. A sub-brand of VisualArts, Key are also famed for creating Kanon, AIR, CLANNAD, Little Busters!, Rewrite, and Angel Beats!
- 5

Harmonia Full HD Edition
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Simulation with Harmonia.
Set in a war-torn world in the distant future, the sci-fi kinetic novel "Harmonia" follows a mechanical boy and a human girl as they find their way to each other's hearts. Key's 15th anniversary title is back with full voice and FHD resolution, including the main character!
- 6

Muv-Luv Alternative
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Casual with Harmonia.
Playtime's over. Time for despair. Experience the definitive version of a masterpiece in the Muv-Luv trilogy's thrilling conclusion. Note: therapy not included.
- 7

planetarian: Snow Globe
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Simulation with Harmonia.
"planetarian: Snow Globe," the prequel to Key's sci-fi kinetic novel "planetarian: The Reverie of a Little Planet," is now available with binaural audio support! Enjoy the story of a companion robot and her coworkers at a planetarium, and the simple joys they find in their everyday lives.
- 8

G-senjou no Maou - The Devil on G-String
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Simulation with Harmonia.
You play as Azai Kyousuke, the son of an infamous gangster. Kyousuke knows what he likes and lets nothing stand in his way in getting what he wants. Referred to as God by his classmates, he often enjoys listening to Bach and "working" part time for his stepfather.
- 9

Rewrite+
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Casual with Harmonia.
In this city built upon the ideal coexistence of civilization and the environment, Tennouji Kotarou spends his days with his friends, Kanbe Kotori and Yoshino Haruhiko. In this peaceful city, a tumultuous event shakes the foundations of Kazamatsuri once a year.
- 10

CLANNAD
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Casual with Harmonia.
From the world renowned visual novel studio Key, the highly rated story of CLANNAD is now available on Steam! Improved visuals, achievement integration, and Dangopedia make this the best version of CLANNAD to date.
- 11

Summer Pockets
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Casual with Harmonia.
From the creators of Angel Beats! and CLANNAD, Key, comes their latest emotional, award-winning journey. Follow protagonist Takahara Hairi as he travels to the secluded island Torishirojima, where he rediscovers what it means to enjoy summer vacation.
- 12

Little Busters! English Edition
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Simulation with Harmonia.
Capturing the hearts of countless fans since 2007, Little Busters! is an emotional visual novel from Key, the minds behind Angel Beats! and CLANNAD. This special English release supports touch controls and dynamic switching between English and Japanese text, and is in HD for the first time on PC.
- 13

LOOPERS
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Simulation with Harmonia.
Tyler is a high schooler on a mission. He's going to use every minute of summer vacation to go on as many GPS-assisted scavenger hunts as possible. After running into some old friends during one of these hunts, strange things start happening: The day resets and today plays out exactly like yesterday
- 14

Tomoyo After ~It's a Wonderful Life~ English Edition
Single-player alternative to Harmonia — playable solo, no multiplayer required. Shares Adventure and Casual with Harmonia.
From renowned visual novel studio Key, this is the sequel to the highly acclaimed visual novel CLANNAD. Featuring a truly memorable continuation to Tomoya and Tomoyo's journey, Tomoyo After promises to draw you even further into CLANNAD's world.