RUST - "STARTUP" ERROR

Hi guys!
I have “startup” problem. I bought Rust yesterday and tried almost everything. When I run the game, it shows that smiley-thingy and then drops. Tried reinstall, run it like 100 times, directx update, drivers update, windows update, administration rights, compatibility modes, check integrity, steam reinstall, dozen of win restart…experimental works pretty well. Can anyone help me? I don’t know what to do now.

Win 7, ATI graphic, 4gb ram.

Thank you!