Place Towers to defeat the blob things. Hover over a tower to see what it does. Click a tower to upgrade or sell it. Hover over upgrades to see what they do. The blob things come from the top right of any map.
All of this is my own programming! This game is FINISHED!!!!! If you were wondering why you can't find YeloBox Games- Tower Defence 1, read this: There is a tower defence 1 but it is so terrible that I didn't bother to share it (it was made in Scratch 1.4 so I couldn't make clones).