Friend of mine can only use one hand, need a list of fun mouse only games.

Hmm. Here are some possibilities:

Dungeons of Dredmor
Age of Empires II HD
FTL
XCOM: EU
Spacebase DF-9
Don't Starve
Sim City 4
Botanicula
Machinarium
Blackwell series
Gemini Rue
Primodia
Civilization (IV & V)
Legend of Grimrock
Defense Grid
Spiderweb Software games (Avadon, Geneforce, etc.)
Total War (Rome/Medieval II/Shogun II)
Myst series
Solar 2
Superbrothers: Sword and Sworcery
Supreme Commander
Command & Conquer
Tropico 3/4

I don't remember 100% if these can all be played one-handed/mouse only, but they're all pretty decent quality and worth checking out. Hope your buddy likes Adventure and strategy games!

Deponia Trilogy FTW !

Point n click games would be great. Some clssics could come in handy, they may look outdated but they are awesome:
The Secret of Monkey Island
Monkey Island 2
The Curse of Monkey Island
Full Throttle (altough it may have had a bike fight that involved using arrows ans space bar at the same time, can't rememeber)
Sam & Max
The Day of the Tentacle

AOE Series!

Critter Crunch and Reus

The Walking Dead.
Plague Inc: Evolved.

I recommend you getting Civilization V instead of IV... the interface is much better for playing with only one hand.

Divekick is a fighting game played only with two buttons, I believe it will be very playable for him, especially because any two buttons can be assigned (keyboard, mouse, controller, etc).

Chawp Free & fun.

Off your maybes list, Jamestown is definitely playable with mouse only.

Not on your list, but I believe they've all three been in bundles recently:

Ballpoint Universe: Infinite is playable mouse-only, and also has a gorgeous art style.

Reus looks to be playable ALMOST entirely using the mouse. Pausing requires space bar. (I only played through the first tutorial to refresh my memory, someone correct me if I'm wrong)

Hack Slash Loot is designed to be played with a mouse, but I'd leave it unless you can get a really good deal. It's extremely luck based and unforgiving, even for a roguelike.

I recommend most adventure games. Point & Click games are mostly all playable with just a mouse. Ofc they're not for everyone. For example Still Life games are missing from your list, and the masterpieces The Longest Journey and Dreamfall.

It's not really a mouse only game, but Burnout Paradise can be played only using one hand on the keyboard. Cthulhu Saves the World + Breath of Death can be played just using hand on keyboard as well, I'm pretty sure.

Not sure if this was mentioned before, but The Wolf Among us, The Walking Dead made by TellTale Games and keep an eye on future releases from them.

Not sure if this was mentioned before, but The Wolf Among us, The Walking Dead made by TellTale Games and keep an eye on future releases from them.

If I recall correctly, Phantasy Star Online could be played using only your right hand on the NumPad, maybe arrow keys as well. Maybe he can set up similar games to use the NumPad for controls?

If I remember correctly, these can be played with only a mouse/one hand:

Commandos series
Puzzle quest series (I love these)
Draw a Stickman: Epic
Crayon Physics Deluxe
...and I don't know if Scribblenauts have the option of virtual keyboard input.

Hope this helps and the best of luck to you and your friend :)

I've once seen a forum post from one guy with the same problem as your friend, he played classic Tomb Raiders (from first game to Angel of Darkness) and was pretty content with them. I am a big fan of those as well and can confirm that while it will take time to get used to it (hell, most modern gamers even with both good hands will have trouble adjusting to TR's controls), but it should be perfectly playable. It only uses keyboard anyway, and the controls can be easily remapped for one hand.

Obviously, the games themselves are pretty old, but they are still awesome.

Definitely add 'Papers, Please' it's amazing!!
Also add GameDevTycoon - what a game!! :)

Not played them but they caught my interest
Ghost Master
Serena (free game)

I only have 1 arm and I am able to play all games that can be mapped to a mouse with enough buttons or a G35 Gamepad. (Plus I am stuck lying flat in bed. And you always miss out on some functions that can not be mapped.) Granted some become much harder to play then if we had two hands but you still can play. Though of course turned based games are the easiest. If he like the Civilization series Civ V is the way to go.

I can't believe no one's said this yet but: any older adventure game. Rich stories, fun gameplay, good humour, and all playable with only your right hand. Some examples that come to mind (and amazingly haven't been named yet):

• Curse of Monkey Island (and the other Monkey Island games)
• Beneath a Steel Sky
• The Dig
• Loom
• Full Throttle

Those are all perfect to play one-handed, and are all fun(ny) as hell! :D

I hope he makes a full recovery man.

Rag Doll Kung Fu! The entire concept is to control solely via mouse, was also the first indie game to be released on Steam. http://store.steampowered.com/app/1002/

Still life 1 & 2

make a controller where you can control with one hand! ;)

Heroes of might and magic VI

Any visual novel under the sky :) Any turn based game. :) Most rts (some are too micro heavy to be enjoyed with one hand)