Scratch 2.0 Game Development Hotshot: Get up to date with Scratch 2.0 and build brilliant games without having to code. Including 10 exciting projects that cover most game genres, you'll quickly learn the sophisticated possibilities of Scratch. Have fun!

We will use the cloning tools again to create hordes of enemies to fight. We will also use these tools to create cannons and cannonballs. It's easy to reuse assets from other projects in Scratch 2.0. The new Backpack feature allows you to easily exchange assets between projects. How this works will be demonstrated in this project.

Because the placement and the route to walk is important in this kind of game, we will start with the creation of the background. To the left of the Sprites window, you will see a separate picture. Underneath is the word Stage and another word, the name of the picture that's being shown. This picture is white when you start a new project because nothing is drawn on it yet. The following is an example with our background image already drawn in:

We will quickly create an enemy sprite to make use of the background we just drew. These enemies will follow the path drawn in the background. Because the background image is fixed, we can determine exactly where the turns are. We will use a simple movement script that sends the enemies along the path from one end of the stage to the other. Like with the targets in the previous project, we will use a base object that creates clones of itself that will actually show up on stage.

Now that we have enemies running around our game, we need to find a way to stop them. To do this, let's use the tried and tested way of shooting them to bits. In our last game, we already made something to shoot with—the cannon and the cannonball. We can easily reuse these sprites in this game and write new scripts for them.

So we can now place cannons that shoot cannonballs in the direction of the mouse cursor. But we still aren't hitting any enemies. Let's quickly fix that problem.

Limiting the offensive power of the player helps to make the game a bit more challenging. But a single group of five enemies isn't much of an attack force to withstand. Let's give the player some more work to do by increasing the number of enemies and then create more enemy variants.

Defeating the enemies is not enough. We need a solid goal to fight for. We will create this in the form of a base at the end of the road. The enemies will try to reach the base, decreasing its health with each enemy that enters it. The player must try to stop the enemies before they reach the base.

We now have a decent horde of enemies threatening our base. There is still one problem though. The player can place cannons at their leisure. So they can quickly build up an impenetrable barrage of artillery. No horde could survive that onslaught.

Just one more thing to do to finish the game. At the moment, the enemies can win the game by destroying the base. But the player can't really win the game. There's no clear end state to kill all the enemies. To finish the game, we will determine fixed winning and losing conditions and add a game screen to clearly tell the player whether they have won or lost the game.

We created a very solid base for a Tower Defense game. This example showed how you can make an interesting, seemingly complex game if you just take it one step at a time. By working on one game object, thinking about what it should be doing, how you can achieve that, and then building the scripts, you can create stunning results without the need to have a grand overview of the game before you start. Many games allow incremental changes and additions, making the game more complex and interesting with each step. Our finished game shows a colorful parade of enemies as seen in the following screenshot. We better stop them from reaching their destination.

That concludes this tutorial. But there are still many more things you can do with this game.

First of all, you can play endlessly with the variables to create a different game challenge, change the number of enemy waves, change the number of enemies in the game, or how they behave. You can change and test building funds to find the perfect difficulty level.

You can improve the graphics by adding more color and texture to the sprites. You could draw creepy faces on the enemies to make them look more like creatures.

And then, you could also add more levels in the game, change the background, and relocate the platforms and the base. Of course you have to achieve this with scripts since each level requires an update of placements and walking routes.