I also discovered this series via Konami's Stinger on the NES. I was initially put off by it, thinking the theme was dumb, but then discovered that the game was very good, and the powerup system fun, if rather odd.
I picked up a used famicom cart of twinbee at a lter time, but that's about the extent of my experience. I want to get the PCE one. They're fun, if strange, little shooters. I remember beating Stinger a few times back in the day. Good game.