What is Scirra Arcade?

I was browsing the arcade , and dunno what is the purpose of this website. because all the games seems to be free. Can anyone explain the pusrpose of this site? thank you

It's quite obviously for testing and showcasing what users have done, or are attempting to do. It is not meant to be / replace an actual store.

The quality, however, varies greatly.

From the page :

Scirra Arcade is an online HTML5 arcade for games made with Construct 2. All authors have verified that they own the rights to all uploaded content.

Being free or paid has nothing to do with the arcade. It's just a way for C2 developers to upload their games to an arcade dedicated to games made with C2. And C2 is a game development engine (or tool).

Alright , so if i want to get attention, i could upload my demo there. thanks

Well, sort of, but not really. Not with the new version of C2, because they change how projects are exported. If I were you, I would wait until the new version of the C2 Arcade. Until then, there's plenty of HTML5 game portals in which you can get all the attention you need (Newgrounds, Gamejolt, etc)

thank you for advice. i will use arcade as well. Because here is a lot of talented people whos critics will help make it better