I personally believe that every level in most action games should finish with a big, bad boss! And is there a better genre then shmup to really take benefits form that idea? In designing levels I take the last battle very seriously. As the stages progress enemies get tougher and tougher, and bullet density increases. The organized chaos culminates at every level's ending, sometimes leading to a small pre-boss, and finishing with a proper boss. Every boss has certain stages. Each stage has distinct bullet patterns. Most bosses are majestic in size, they are pretty easy to hit (bigger can be better). What is difficult is avoiding attacks. Attacks usually combine 2 or 3 types of bullet patterns, always with bullets of different colors (see my other news why this is important). Even though attacks are structured, there is usually a random element that "keeps players on their toes".
Here is a short video below showing ending of Level 2 with placeholders:
The game will include 8 levels, and so far I have pretty solid design for about 5 levels. Three last levels remain, and then working on game art. If you like don't forget to comment!