Soldnder X is an horizontal shooting game produced by the famous online import game shop Play Asia. Seems that  the game quality is pretty high. Actually at the beginning I feared that this game would have been just a doujin game translated in english and professionally packaged. Instead the project turned out to be the first "must have" game for shooting lovers since the last Dreamcast shooters released last year...

Main features of this game:

• 720p at 60 fps
  
• 2-Player Co-Op Play (simultaneously)
• Classic design, yet state-of-the-art shooter technology
• Unique upgrade weapon system with five standard weapon types
• Never before seen tactical elements such as chaining, effectiveness system, 'berserker' mode and much more
• More than 20 extras (with both positive and negative effects!)
• Addictive collection quests
• Over-the-top boss fights
• Features a superb soundtrack and sound effects
• Bi-lingual story mode (English/Japanese)
• Online high score ranking
• Constant frame rate (60fps)

This is a You Tube video preview  ( this is the original NicoNico version).