Possibly a KM game, I'm not sure.

[Pooka]

I don't know what this is, but it looks like this, and the sprite looks like a Dungeoneer.

Is this one of the official games that I never played? Or something else?

[HStorm]

I've played that a few times, I think you can still get it from various Abandonware sites. It's not related to KM, but it's true that the title and helmet make it eerily similar. But it's actually a scrolling 2D shoot-em-up, the gameplay isn't anything remotely like KM as we know it.