Last week I had finished the design for the first boss, and here’s what it looks like in game:

It took me quite a while to get it to show correctly in the game. The object consists of twelve separate sprites, and it took a lot of trial and error to get them all to line up correctly. The reason it has so many different sprites is that the gun turrets have to be able to rotate and different components can be destroyed separately. This feature will also be present on other enemies in future levels.
For now, the ship moves across the screen and aims at the player. Firing hasn’t been implemented yet, but the shield works and protects the craft. The next step now is making the gun turrets shoot at the player, making them take hits and explode and dropping the shield when both turrets have been destroyed.