Can you help me remember a game?

[Sgt Poppinfresh]

Hi
I'm trying to find out the name of a game and its really annoying me and I was hoping someone would know what I'm taking about. It was a sidescrolling shooting-game for the PS1 where you shot aliens and it had co-op play, you could also upgrade your guns to shoot lightning and cutting blades. Basically like Contra except I'm sure it wasn't a diferent version.
Thanks

 

[barryween]

Metal Slug? That's all i can think of... Aliens were enemies in one of the Metal Slug games, but I doubt that's what you are referring to. Were the upgrades permanent? or like, temporary?

 

[Sgt Poppinfresh]

The upgrades lasted until you died and I remember there was a glitch that you couldn't get past one of levels sometimes because a door wouldn't open. Thanks for the quick reply.

 

[Skuffyshootster]

Hello Kitty Island Adventure, definitely.

 

[Sgt Poppinfresh]

Thanks for the replies but Hello Kitty's first level was impossible to beat and I gave up.