Silence of the Siren Early Access is available from today on Steam, for 25.49€
From what I know the game was playable even a year ago on Gamescon, so it should been pretty mature right now.
For more you can watch devs commented streams on the Steam page or join their Discord.
The inspiration from Heroes is breathtaking. But, it's something else. Will you try it, are you tempted?
A bit later edit:
Modding will be available a bit later but definitively it's being counted on. See a lots of interesting stuff answered here.
You can discuss the topic here.