They are... approching... Surging......Today...... Collect resources and establish a defense line before darkAnd then Facing countless enemies Features 40+distinctive Towers, almost every type has unique upgrades! 40+meticulously designed levels, 40+challenges that combine difficulty and fun! Countless enemies Minimalist design style, user-friendly gameplay, diverse difficulty levels

Go to: http://store.steampowered.com/ and download STEAM client Click "Install Steam" (from the upper right corner) Install and start application, login with your Account name and Password (create one if you don't have). Please follow these instructions to activate a new retail purchase on Steam: Launch Steam and log into your Steam account. Click the Games Menu. Choose Activate a Product on Steam... Follow the onscreen instructions to complete the process. After successful code verification go to the "LIBRARY" tab and start downloading.