More ships are planned, but not implemented yet. I want to use more ships from The Big Spaceship Builder. The plan is that you will play another invader every wave and fight against the previous invader that invaded the planet (That means that you will fight yourself). That's also the reason why I named the game Invaderion, Invaderion is a blend word from "Invader Invasion".
You don't have health in this game, you explode immediatelly when you get hit. You have 5 lifes per wave though that are shown at the top right corner. If you want to see your hitbox in red you have to hold "Left Shift" - then you enter focus mode and you also move slower. With focus you can get past wave 4.