Without Tomohiro Nishikado, there would be no 'shmup'. When he created the legendary Space Invaders in 1978, he effectively birthed an entire genre, and every 2D shooter created since owes a debt to that single-screen smash-hit.
However, in an interview with Time Extension, Nishikado reveals that he's less than enthused about how the genre has evolved in recent times, with "bullet hell" (or "danmaku") shooters being the most popular sub-genre in the realm of shmups.
Speaking about the impact of Space Invaders and the games it has inspired over the decades, Nishikado explains that he was impressed by Namco's Galaxian and that he "really liked" Xevious, but he's less keen on the dense projectile patterns of modern shooters:
As for more modern danmaku-type games, I don't really like these. However, they are probably an inevitable result of players becoming more skilled with these types of shooting games, and developers are forced to outdo them in some way. This is some kind of never-ending battle.
Actually, the first prototype of Space Invaders was much easier, as I am not that good at games. However, I let my colleagues test the game, and they all said it was too easy. I was initially worried about making it too hard, but the final version shipped with that difficulty, and everyone seemed to think that was fine. Game balancing is always tricky, but the conflict between gamers and developers forces this kind of evolution. However, I do feel like danmaku is sort of a dead-end functionally.
This is because it gets to a point where newer players cannot enter, and I think this is why modern shooting games have disappeared, as they got too difficult.
Nishikado feels that games which favour "technical strategy" are a more effective way to expand the genre:
Though I have never played myself, games like Radiant Silvergun and Ikaruga, which focus more on technical strategy rather than brute force difficulty, are a better approach. I feel that focusing purely on making a game difficult doesn't help the game bring in a broader audience. Games like Ikaruga are a smarter way to evolve the genre.
You can read the full interview with Nishikado here.