In my opinion it's the gold standard for arcade game design; super easy to understand and pick up and play, with the replay value being not just because of difficulty, but also because of the underlying depth and complexity and secrets to uncover which can result in even replaying early levels being a different experience now that you can utilise those hidden mechanics. It's why i'm very fond of shoot-em-ups too!
In my opinion it's the gold standard for arcade game design; super easy to understand and pick up and play, with the replay value being not just because of difficulty, but also because of the underlying depth and complexity and secrets to uncover which can result in even replaying early levels being a different experience now that you can utilise those hidden mechanics. It's why i'm very fond of shoot-em-ups too!
P.S. the story gets even goofier with revelations introduced in Rainbow Islands