One good thing about the Japanese DSi Shop for retro-gaming fans is the availability of old-school sprite-based shooters, with several decent ones to choose from. The G.G. Series already has a few among its number, but they're all different enough that it cannot hurt to add another one: enter Dark Spirts, of the bullet-hell variety.
Players control a figure in a black trench coat flying through a cityscape, wielding eldritch magic against robotic and demonic foes. Whilst the rank-and-file baddies aren't that interesting, there's not many of them and the focus is really on the boss battles. You can only take five hits in your single life, so you'll want to take the weak enemies seriously to conserve your strength for the main event in each stage. Though the first fight has some rather poor hit detection (shots will pass through you about half the time), subsequent battles are quite challenging and take a little while to get through as you need to identify the weak spots and whittle away at defenses before you can start working against their life bars; dodging hails of fire the whole time.
What's thus been described would make for an entertaining shooter, but Dark Spirits' power-up system is what's most interesting to us. The flying figure himself only fires a single bolt but he has four floating spheres at his disposal that can fire in a concentrated burst straight-ahead or in a forward or rearward-facing spread; each of the three firing modes triggered by a different button press as the situation dictates. Rather than power-ups that simply make the standard attack more powerful, the colour-coded power-ups released by some enemies are used to upgrade or change the shots fired by the individual spheres. These will have definite strategic uses, e.g., a blue cube which will destroy smaller enemy shots or a yellow fireball that seems to have a limited homing ability. You simply touch a sphere against the power-up as it passes by to change the type; if you touch a sphere with the same upgrade twice the attack will be more powerful and the sphere will transform to indicate this. It's really quite clever and adds a sort of RPG-on-the-fly feeling to the game as you figure out what mix of weapons you like best, leading players to the odd situation of actively avoiding power-ups in order to prevent their arsenal changing accidentally.
Graphically it's the kind of impressive 2D we've come to expect from Suzak with highly detailed, colourful sprites and fluid animation. Whilst the hit detection issues are a bit disappointing initially, they seem restricted to the first boss and the rest of the experience is quite solid with the unique power-up system and flexible firing patterns being the real stars of the show. It's another great budget release from Genterprise, so if you have the means you should definitely check it out.