This week marks the release of two awesome shoot'em ups to the App Store: Cave's vertical-scrolling bullet hell title Dodonpachi Resurrection, and Irem's horizontal-scrolling classic R-Type. Both arcade conversions are available for iPhone, iPad, and iPod Touch (though Dodonpachi requires an iPhone 4/3GS, and a 3rd gen iPod Touch).

Priced at $1.99, R-Type offers three control options: tilt, touch, and virtual directional pad (which tilts and slightly shrinks the gameplay screen to give it an arcade cabinet look). It also features an auto-fire option and a mode with unlimited lives to make the infamously difficult game a bit more approachable to newcomers.

Dodonpachi Resurrection is a bit more expensive with a launch price of $4.99 (rising to $8.99 next week). As covered before, it offers iPhone and Arcade modes, a Practice mode, a new SM Scoring System, new music by Kenichi Maeyamada and Shoichiro Hirata, leaderboards, achievements, and more.

So long as you're splurging on new iOS games, maybe you'll also want to pick up Sega's Phantasy Star II port ($2.99), too?