Coblyn is a Boulder Dash remake with prerendered 3D graphics. It's a sidescroller where the goal is to reach the exit after unlocking it by collecting a certain threshold of diamonds. Bombs, falling boulders, and a variety of other obstacles and enemies (including a time limit) make this a rather difficult endeavor.
It's rather absurd to approach the game at face value, since you control an orange-shirted man with a lust for gigantic diamonds and a deathly fear of insects. (I guess I'd be scared of butterflies too if touching them meant a massive, inescapable explosion.) The real value here is in the time-tested (or maybe just nostalgic) gameplay and the compatibility with thousands of custom levels designed for Boulder Dash and its ilk. Despite this emergent variety, I find it hard to engage in and enjoy Coblyn with its nonsensical physics, its absence of context, and its lack of guidance in where to start playing.
Sam's Protip: Don't get crushed by a falling diamond; it's the most ironic way to die. Death by exploding ladybug is much more acceptable.