I've recently managed to get Playnite working on Ubuntu/Linux Mint using Lutris. I have not tested any other distributions, but I assume it would work on other distros as well. It can launch linux games, but it will not automatically add them, you have to manually add each game individually.
Installing Playnite
First, install Playnite through Lutris with this script https://tinyurl.com/2p83hcjc (I'm still waiting for it to be approved, will update with the proper link once it's approved). Make sure to untick Launch Playnite once the installer has finished. Then launch Playnite from Lutris and go to Settings > Advanced > Performance and check "Disable Hardware Rendering"
Go to wherever you installed Playnite (usually ~/Games/playnite) and create a file called in drive_c/users/[USER]/Desktop called playnite_steam.bat and put this text inside:
And create another file in the same location called playnite_other.bat and put this text inside:
Adding Games
To add a game, do not use the library integrations. Instead, manually add the game by clicking the playnite menu > Add Game > Manually, download the metadata with the Download Metadata button, and go to Installation, tick the "Installed" box, go to Actions, and click add action, and click the select file button next to "Path".
If you are adding a steam game, select "playnite_steam.bat" from before, and them put the steam id of the game in the "Arguments" box (eg. Terraria would be [color=var(--newRedditTheme-monospaceColor)]105600[/color]).
If you are adding a game not from steam, select "playnite_other.bat" from before and put the path to the game executable in the "Arguments" box (do not use ~ use /home/[USER] instead eg. Celeste for me would be /home/rbits/Documents/celeste-linux/celeste).
Then go to scripts, untick all the boxes, and click save.
If you want to add a game from another launcher, I don't currently know how to launch shortcuts from Playnite in Linux, so either use playnite_other.bat and in the Arguments box add the path to the launcher followed by any arguments needed to launch the specific game, or add it to steam and follow the steam instructions.
Now the game is added to Playnite. Press play and it will launch the game!
It's quite inconvenient having to manually add each game, and I know this might defeat the purpose of Playnite for some people, but I use Playnite because of the great themes and aesthetics, and I haven't found any good alternative for Linux, so this works great for me. At least until Playnite officially releases on Linux... hopefully. Once I learn how library integrations work, I might try to make an extension that does all this automatically. Otherwise, if someone else knows how to make Playnite extensions, I would love if someone could make an extension that does this automatically. I haven't been able to get any davidkgriggs themes to work, which is disappointing, but other themes seem to work fine.
Edit: Updated method to add a game to make it much more simple. Now you only need 2 .bat files total, rather than having to create a .bat file for every game
Installing Playnite
First, install Playnite through Lutris with this script https://tinyurl.com/2p83hcjc (I'm still waiting for it to be approved, will update with the proper link once it's approved). Make sure to untick Launch Playnite once the installer has finished. Then launch Playnite from Lutris and go to Settings > Advanced > Performance and check "Disable Hardware Rendering"
Go to wherever you installed Playnite (usually ~/Games/playnite) and create a file called in drive_c/users/[USER]/Desktop called playnite_steam.bat and put this text inside:
cmd /c start /unix /usr/games/steam steam://rungameid/%1
cmd /c start /unix %1
Adding Games
To add a game, do not use the library integrations. Instead, manually add the game by clicking the playnite menu > Add Game > Manually, download the metadata with the Download Metadata button, and go to Installation, tick the "Installed" box, go to Actions, and click add action, and click the select file button next to "Path".
If you are adding a steam game, select "playnite_steam.bat" from before, and them put the steam id of the game in the "Arguments" box (eg. Terraria would be [color=var(--newRedditTheme-monospaceColor)]105600[/color]).
If you are adding a game not from steam, select "playnite_other.bat" from before and put the path to the game executable in the "Arguments" box (do not use ~ use /home/[USER] instead eg. Celeste for me would be /home/rbits/Documents/celeste-linux/celeste).
Then go to scripts, untick all the boxes, and click save.
If you want to add a game from another launcher, I don't currently know how to launch shortcuts from Playnite in Linux, so either use playnite_other.bat and in the Arguments box add the path to the launcher followed by any arguments needed to launch the specific game, or add it to steam and follow the steam instructions.
Now the game is added to Playnite. Press play and it will launch the game!
It's quite inconvenient having to manually add each game, and I know this might defeat the purpose of Playnite for some people, but I use Playnite because of the great themes and aesthetics, and I haven't found any good alternative for Linux, so this works great for me. At least until Playnite officially releases on Linux... hopefully. Once I learn how library integrations work, I might try to make an extension that does all this automatically. Otherwise, if someone else knows how to make Playnite extensions, I would love if someone could make an extension that does this automatically. I haven't been able to get any davidkgriggs themes to work, which is disappointing, but other themes seem to work fine.
Edit: Updated method to add a game to make it much more simple. Now you only need 2 .bat files total, rather than having to create a .bat file for every game