Press the up and down arrows to select a tool then click on a block to raise/lower it. The maximum height is 5 and min is 1. The ruler button changes the dimensions of the terrain block. Press the odd looking square to save/load. You can paste your codes in the comments. Here's a cool one: 331 211 111
--- How does this work? --- This program uses a "height map", which is a grid of numbers that tells the program how high to draw each block. The maximum height is 5, but you can change this in the "render terrain" block.