After a seven-level warmup with Ring Blade, a bullet-hell shooter with a twist, I found my right index finger getting that weird burning-inside/cold-to-the-touch feeling. It's a good thing, I think.

Ring Blade, from MindTrip Studios, is a mobile game right in the sweet spot of any shooter fan with an iPhone. It sticks to a simple gameplay mechanic and layers on power-ups, tougher enemies and visual complexity after that. It also offers 30 levels for just 99 cents, plenty of value for an impulse purchase.

The difference in this shooter is your bank-shot capability with the titular Ring Blades, which will be necessary when you try to angle the attack around a boss or mini-boss's defenses to take it out from the unguarded side. In the standard attack waves, it's a cool variant on the constantly firing blaster one expects in bullet hell; in this case the continuous damage is done by a blade careening off the side of the arena. If you have three blades (or five, with a power up) winging off the sides at shallow angles you'll see what I mean. Even though only five shots are live, they're mopping up while you get out of the way of anything coming through.

Your craft has a health meter, so it's not a one-hit death, but if Ring Blade feels unfamiliar it's because your finger can only move along one axis at a time. There's no moving and shooting, because you're either flicking up or to the side. I had a tendency to park myself in one location and fire from it, moving only when the waves descended on that position.

For shmup fans, Ring Blade offers a slight variant on the genre, one that takes advantage of the iOS multitouch screen while still sensibly staying within the platform's limitations.

Ring Blade [iTunes App Store]