Such depth, however, is present in the gameplay too. Let me explain. Apart from the usual main weapon, there's a secondary one, called Thunder, with two uses: if you press both buttons together, a powerful bolt of energy will inflict great damage to enemies in front of the ship, protecting it from enemy shots too. If the second button alone is tapped, it will generate a series of lightning bolts that will strike the enemies that fly lower, in the background. This is the funniest aspect of the game: you will be able to destroy many enemies before they can fly up and reach you; some can be destroyed only this way. Often, you can even destroy squadrons of ships that are just passing, ignoring you, for the sake of a bigger score :) And, beware: the bosses have a nasty tendency of escaping and bombarding you from safe places! There are only few types of power-ups, but the incredibly fun Thunder weapon won't make you desire more of them.

I have two complaints: the beauty of the graphics is a bit marred by the low resolution (no way to use a higher one, sadly, unless you want to play in a stamp-sized windows), and I found this two-level demo not too difficult. This, however, makes the game more accessible to the less-experienced players. Aside from this, Kamui is surely one of the best "Dojin" (amateur) games from Japan, and a must-play if you like 2D shooters.

Note: the download link below leads to the official site, where you can download the trial version for free. The full version of the game can be bought at the Himeya Shop, in the Windows JP --> Dojin Soft section.