I randomly came across some videos showing this game, so I then played the rom, which I had for years and never saw, and ended up buying a copy off eBay. It's a pretty enjoyable side scrolling almost-platformer sort of shooter that's easy to pick up and play, but does get tougher once you hit the 4th boss. I think it's a very classic style game that fits perfectly within the PCE era. I recommend it if you haven't tried it yet. I'm not sure how long the game is, but it can be had for around $10 or so before shipping.