Use WASD or the Arrow Keys to move. To build, click on the build button, hover your mouse over the grid and click anywhere on it to place it. To change a block's appearance, click on the button that says "block" to access the block editor. To delete, click on the trash bin icon, then click on a block to delete it.
Was bored again so I made something in a few days, I don't except much from this, I just built this as kind of a test.