How can I create the game, which can be played by several users?
I mean that players have to see each other at one stage.
Like in wellknown mmorpg games.
You should use the peer to peer multiplayer functions integrated in Construct 2, you could use something like Parse or Firebase if you want to store variables (like player coins or credits) securely.
Construct 2 is actually perfect for MMORPG's.
Develop games in your browser. Powerful, performant & highly capable.
if your asking that... you should read this section and this