Thank you guys for reporting about this problem. To resolve this issue we need more technical info about it. But first make sure that you followed these basic steps:
1. Try to restart the game
2. Verify Blockade's cache integrity ( HOW TO )
3. Delete Unity's cache( HOW TO )
4. Try to reinstall the game

If these steps didn't help then email us (b3dcrashreports@gmail.com) with topic titled "Error: Steam not launched"(IMPORTANT!) and in mail body specify this info:

1. Your PC specs
2. Your operating system
3. Is it make difference to start the game from the desktop shortcut or from the Steam Library?
4. Your antivirus system. Did you try to temporarly shut it down and then start the game? Is that make difference?
5. Additional info or video representing the problem(optional).
6. Necessarily attach the file "output_log.txt" that can be found in the game's folder (...\Blockade3d\main_Data\)

UPDATE
Patch 15.07.16 fixed Error Steam not launched. Those who had this problem before please comment if it is fixed for you now. Don't forget to check cache integrity before start the game.

Thank you.