Alpacky (Alien) appears as a boss here for the first time. It has much slower attack rate than Camelle, but has more hp and deals a lot more damage.
For chapter 1: This level can be very hard to pull off without Bahamut or an uber, so it is recommended to have Bahamut at this point.
For chapter 2: First, spam Wall Cat/Eraser Cat. Once your wallet is full, spawn Bahamut, Valkyrie and your uber (If you have one). Be wary that if you still don't have any anti alien treasures, Cyberhorn will have a devastating 840,000 hp and 15,400 damage! This will make the level nearly impossible, so it is advised to have both anti alien treasures from Chapter 1.
For chapter 3: First, stall with Eraser Cat and Crazed Wall Cat .Then, once Alpacky spawns, stop upgrading your wallet and start spawning strong units, Bahamut and of course, meatshields.
Once Cybehorn dies, go all out on Alpacky. It wont last long if you have a lot of anti aliens.