Fans of 2D scrolling shooters of the Xevious style may want to have a look at EuiBeom Hwang's recent App Store release, Neocell Fighters [link].
As the title might suggest, Neocell Fighters has a biological theme--think Fantastic Voyage. While there's not much story directly presented by the developer, it's clear from the game's well done graphics that the player controls a vessle travelling through a living being, destroying an onslaught of cellular enemies.
Neocell Fighters features accelerometer-based ship control with a tap to the screen to fire. And, while I generally prefer touch control for 2D shooters, the game's accelerometer controls work well enough. There are two ship controls modes to choose from: one that lock the ship at the bottom of the screen and allows left / right movement only and one that allows movement in all directions. I, personally, find the former to present a more focused and enjoyable game.
The title features multilevel parallax background scrolling as well as left / right playfield drift, reminiscent of classic shooters Raiden and Battle Squadron. The various enemies are graphically larger than those in most shooters, making for a slightly cramped play experience which...well...feels cramped at times, but adds to the difficulty of the title. And this is indeed a rather difficult challenging shooter. Howerver, despite the size of the game sprites, the enemies smoothly dance about the screen at a very quick pace. The game sets itself apart from many of the 2D shooters in the App Store in this regard.
Gameplay in Neocell Fighters ranges across 50 different map areas, each running for about 30 seconds. Various eliminated enemies release power-ups that bestow upgraded weapons upon the player's craft. Enemies consist of swirling fighters as well as turrets mounted to the scrolling backdrop. At different points in the game's various areas' boss-type enemies must be contended with.
Neocell Fighters isn't the perfect shooter, but for fans of the genre it's certainly worth it's $0.99 (limited introductory) price.
See the developer's gameplay video:
App Store Link: Neocell Fighters, $0.99 (limited time)