Joe & Mac's SNES port padded the boss-rush-esque original into a full-on platformer, and it became the series' direction for Data East's next two installments. Congo's Caper subdues the run-and-gun elements in favor for movement controls and level structure that's more comparable to SMB. Gone are the pudgy, dopey duo from 1 and new is a shonen-styled monkey boy: A sign of changing times and audiences, kicking out the comedic Neanderthals for a character that's both more appealing and projectable to its then target audience. Congo's sharp movements, high jumping and fashionable blue hair call Megaman to mind.
But the transition to SMB-style structure and gameplay brings a lack of focus. Stages are divided into worlds with sub-acts, each way shorter than what feels natural while also lacking an identity. Layouts constantly re-use assets between worlds, and the player's mechanics don't feel well-explored. One moment that best exemplifies these quirks is 3-4, an auto-scrolling pirate stage that moves the camera towards the starboard, only to reverse, go underwater and underneath the boat, only to drag you right back where you thought it would originally take you.
Among other issues, hitboxes are mapped horribly. Jenny already pointed out the final boss, but this applies on lesser levels to most other bosses and enemies too - sometimes in your favor (you can kill the world 1 t-rex by swing at the thin air in front of his belly), and other times not. This even feeds into platforming; there's a glitch where you sometimes can't jump while running down a slope, presumably because the game isn't registering that you're on the ground each tick. The high jump can be an inconvenience too, as its so high it drags your viewport away from the ground and you can't always tell where you'll land until it's too late. There's an entire gameplay gimmick with using your swing to stun cavemen and then launch them to break blocks, but it's used only in the first and fifth worlds for some reason. It all amounts to Congo feeling a lot lower-budget than J&M 1, despite the better performance and cleaner art.
Nothing you're missing out on if you don't play it but it's still perfectly safe and comfortable in spite of its issues. The frivolity of it all makes it a good play for low-energy sessions.
