Recycled concepts are nothing new in the games industry. For a classic example, the company Color Dreams, responsible for a ton of unlicensed NES games, took most of its existing games, repackaged them with Christian themes, and sold them again under the company name Wisdom Tree. For a more recent example, look at all the various series and sub-series that Koei spawned from the success of Dynasty Warriors 2. Quite simply, if you've played one Warriors game (aside from the first), you've played them all. Developer Vic Tokai is no stranger to recycling games. In 1988, they developed Kid Kool for the NES which sucked. In 1989, they reworked and fixed Kid Kool into the game Psycho Fox on the Sega Master System. Finally, the same game was reworked and enhanced again to create Decap Attack, easily the best the concept could get.
In Decap Attack, you play a headless mummy named Chuck D. Head (Don't get it yet? You will.) resurrected by Dr. Frank N. Stein (Get it?) to go after the Underworld demon Max D. Cap (Okay, Vic Tokai, enough with the dumb puns!). The world looks like a sillier take on Halloweentown from The Nightmare Before Christmas and looks great even now. The normal enemies are pretty standard for this type of setting and work well. Even the soundtrack is awesome which says a lot since the Genesis was never that strong in the audio department. More effort is on display here than in Vic Tokai's 8-bit outings.
The gameplay is simple and common for 16-bit platformers but works great. Enemies can be stomped on (with the obvious exceptions being enemies with spikes on their backs), or they can be headbutted when you expel Chuck's face from his chest... Did I mention this game is weird? Chuck can also collect skulls that can be thrown onto his torso to provide protection from a hit or can be flung at distant enemies like a boomerang. Every level has three stages with a cool-looking boss fight at the end of the third stage. The gameplay is much more satisfying here than in Kid Kool.
There are a couple of skeletons in this game's closet here, though. Chuck is rather slow, disappointing for those used to Sonic the Hedgehog's speed. While the artwork is awesome, I do wish the game wasn't zoomed in so much. I had more than a few cheap pitfall-related deaths that could've been avoided if the visuals zoomed out a little. Speaking of deaths, the worst thing is a lack of mid-stage checkpoints. If you get killed in the boss fight, you go back to the start of the stage. That gets very frustrating near the end of the game.
Decap Attack is one of the Genesis' hidden gems. It was largely ignored back then in favor of a certain blue hedgehog, but it deserves a second look. Vic Tokai took their initial concept and refined it to create a near-masterpiece. If they tried to refine it any more, they probably would have messed it up. It's a good thing they quit when they were a head. (Sorry, I couldn't avoid that last pun.)