The only platform currently listed is PC, while other platforms were removed, apparently by accident.

I looked into it more and apparently the game has been ported everywhere. There's a list on Wikipedia: https://en.wikipedia.org/wiki/Angry_Birds_(video_game)

The platforms that could be added here include: iOS, Android, 3DS, PSP, X360, PC, WindowsPhone, Web, Mac, Roku, Wii, WiiU, etc. (though obviously iOS and Android are the most important.)

wasn't the game discontinued on mobile?

It is still on mobile

The original game is no longer available in the app stores in the United States, not sure about other countries. Even then, the game's APK file can still be sideloaded onto mobile or played through emulation. On a lot of these platforms it is included in the Angry Birds Trilogy game.

I know that this forum was written about it 2 months ago but we already have Angry Birds Trilogy added to the series, but the category requires passing all levels

Not on play store in uk either

Wait so if we want fo speedrun tbe original on mobile we would have to use angru birds trilogy?

Nvm trilogy isnt on play store either