It's quite clear that the project is far from complete at this stage. However, there are a lot of things that are a core of the game's implementation: the dragging, the scoring, and the grid formation. From here on, it's probably best to continue to iterate on the project and slowly add stuff until it's a fully working prototype with very minimal baseline mechanics working. For example, we could add some enemy spawning, Artificial Intelligence (AI), the user's units automatically moving, and so on.
But as far as this book is concerned, we're going to move on as the point of this chapter was to go straight into a prototype. That's basically what we have here—something we can show our friends and family and say, "Hey, this is what the concept is, and this is what I've got so far." With the prototype, you can gauge things such as the following:
Is the game board too small for the player's fingers?
Is the concept too confusing?
Is it hard to interact with the character?
With...