You may be experiencing worse than expected performance on Steam. This could be because the game cannot find the right compatibility for your graphics card.
To fix this, you can try the following steps:
- Go here: https://helpx.adobe.com/flash-player.html
- Scroll down to "Verify if Flash Player is installed".
- Right-click on the spinning icon, click "Settings" and make sure "Enable Hardware Acceleration" is enabled
If this doesn't work, please check that your Graphics card is not listed as incompatible here (http://helpx.adobe.com/x-productkb/multi/stage3d-unsupported-chipsets-drivers-flash.html). You can also try updating your graphics card drivers to see if it solves the issue.
If you are still having problems please send support a ticket with details about the problem as well as your system specifications.