Since you mentioned Ikaruga, then Im gonna suggest Castle of Shikigami 3. It has 10 unique characters(ships) with different standard attacks, Shikigami attacks and bomb attacks, different story for each character or in 2 player character combo, and a ton of options. Lots of difficulty modes and once you beat the game once you can adjust gamespeed, bullet speed and some other stuff. Best off its only $30
Its not so hard as Ikaruga to beat on normal with some of the best caracters like Roger the International Ninja, but there are so many options you can make it just as hard if not harder. Also Blastworks is pretty decent the missions are nowhere near as fun as CoS3 but you can create your own enemies, levels, bullet patterns, backgrounds and playerships and download otherpeoples at www.blastworksdepot.com
Also by saying you can beat Ikaruga how many credits does it take? cos I can beat it but Its like 13-14, used to be able to do it in about 7 but the last couple of levels get me all the time.
