Use this engine to make your very own level. You only need to modify the letter codes in the "example" block's "create row" blocks. Then, go to the enemy for info on what modifications to make for the path walking sprites. You can always add another tower through the "placement object" sprite, and create a new sprite while you're at it. Make sure you can upgrade it! Or, you can add an enemy or two.
Here's the thing you can remix to create another level.