This game is classified "A" for "AWESOME"!!
Metroid style games are great, but you'll find them everywhere. Your addition of the unique wall climbing mechanic is quite fantastic, and makes for a whole new experience. Undoubtedly many other Metroid style platformer fans have often wished "If only I could climb that wall!", and you have granted them that wish.
Great game chap! I played on EASY cuz it's my uni extrav and i'm fuuuucked :p (well done on including difficulty levels too, for people who just wanna explore and not be bothered with survival tactics - like me!) :D 10/10 (graphics and sound are top nothc too)