I have made more progress on this side project and since it is targeted for mobile I had to make some big changes! I created a script that checks the screen resolution and from that it determines how far apart and where to generate the enemies. I also made it so that you can select how many rows/collumns you can have for the enemies. It also randomly creates 2 different enemies with different materials and health values. I also changed it from landscape to portrait. And I removed the stock standard Unity generated play button and added a big icon which will suit the screen resolution. In the past I have only created games for PC so when I tested this game on my Iphone the text and buttons looked small and terrible. Here is an in game screenshot.
I also added a script that keeps track of how many enemies there are so that when you get to 0 it will spawn more. Next I will be making the enemies fire back!