One of many Apogee side-scrollers that I played as a wee lad on the family PC back in the 90s. I never finished this one, though. Replaying the game on Steam (the first episode's also available for free on the Internet Archive), my guess is this was simply too difficult for me at the time.

As you can see from the poster, Cosmo is a little green dude with suction-cup hands. Much like the Commander Keen games, Crystal Caves, etc., your nominal goal in each level is to reach the exit, but your real goal is to collect as many points and find as many hidden nooks and crannies as you can along the way (levels are often as vertical as they are horizontal). I don't think the points you gather from floating objects do anything, but I still felt compelled to search out point-heavy gems, or work my way toward the invincibility shield in a hidden corner of a cavern beneath the map. In Cosmo's, collecting points and items means jumping. Jumping a lot.

One of the minor drawbacks of the game is Cosmo's movement on the ground, which is a little slow relative to, say, the 2D Mario games that Apogee was clearly aping in the 90s. There's not much fluidity when Cosmo's running around, even if the controls are easy enough to get used to. Cosmo's at his best when he's soaring through the air, collecting point-filled fruits in arcing trails above the treeline, bouncing off monsters or springboards or crates and barrels, which explode with those satisfying Apogee sound effects. The suction-cup hands are a nice mechanic, too, giving you the opportunity to pause mid-air against a wall, or suction-cup-jump your way up a vertical surface.

But the game's difficulty comes from its enemies, who absolutely flood the screen, sometimes raining (literally) from the skies. In this respect, the slow movement of the game is a necessity. Cosmo can take up to four hits before he dies, and there are single-hit health pickups scattered throughout each level, but enemies have a tendency to swarm, and the flying enemies will sometimes follow you halfway across the map if you don't handle them. They're sometimes treacherous to kill, too, as you need to either jump on them (while they're buzzing around, eager to kill you if you're off by a pixel or two) or explode them with bombs (which are tricky to time).

Dying takes you back to the beginning of a level, you can't save mid-level, and you lose any points you gathered before dying, which had the effect for me of discouraging exploration (since I knew I would likely lose any extra points I gathered by venturing into strange areas of the map). I'm probably overplaying the difficulty here. In fairness, I worked my way through the first half of the first episode in about an hour (there are three episodes in all, each with several levels), but as someone who's not the biggest fan of grinding my way through platformers, I don't think I'm going to finish the game.

That said, the enemy variation is impressive and fun. There's inventive stuff here, from the roving rolling balls with angry faces that parachute into the map to the suction-cup monsters that hop their way from surface to surface. And bonus stages, which can be earned by collecting shooting stars that hang about or drop onto the map, give Cosmo a chance to fall through lengthy pits of point pickups and strange flying slugs that reward Cosmo with jewels when he runs into them.

It's a weird little game. But, you can tell the creators had fun with it. So did I, until I slide down an icy hill into an unavoidable swarm of enemies that immediately killed me.