Kero Blaster stands directly in the shadow of not one but two other games by creator Daisuke "Pixel" Amaya. First is Gero Blaster, the original build of Kero Blaster which was announced back in early 2013. Gero Blaster was based on comics that Amaya drew in college about himself as a frog and his girlfriend as a cat. The cat is kidnapped by cyclops aliens and the frog must head off to rescue her. The game looked to be a lot of fun, and was quite far along before Amaya reportedly scrapped the whole thing and rebuilt it as Kero Blaster.
The other game that Kero Blaster has hanging over its head is Cave Story. Released in 2004, Cave Story changed the way many people viewed independent game development. It took Amaya five years to develop the game, and he released it for free. Later, it would receive enhanced ports for WiiWare, DSiWare, 3DS retail, 3DS eShop, and Steam. Fans of the game will tell you that it's one of the greatest Metroidvania titles ever made.
Seeing that Kero Blaster is the first action-platformer that Amaya has released since Cave Story, expectations are understandably high. Ironically, it's diehard fans of Cave Story who may be the most disappointed with Kero Blaster, as they are in for a much shorter, less ambitious experience. That's not to say it's any less worthwhile. If Cave Story is a rock opera, then Kero Blaster is an album of energetic, perfectly paced pop songs. As long as you don't go into one expecting the other, there's no reason you can't enjoy both in equal measure.