DAZE BEFORE CHRISTMAS / Sunsoft / Sega Genesis
I'm still not totally clear on whether this game was actually released in the PAL territories at some point or if it's just a very polished beta that escaped from Black Mesa somehow. The levels are short and the difficulty is generally very easy, pointing to beta status, but then that could just be intentionally child-friendly design. I dunno.
Whatever the case is, this is one of the better platformers on the Genesis. It looks great, with nice animation and some great art between levels. It has great music. The gameplay is very solid. As mentioned, levels are short and generally easy, but there's a whole bunch of them (and there are some at least moderately challenging jumping contests in the later reaches.) It uses a password system, but there seem to be infinite continues from whatever level you bite the bone at.
The premise is that some evil force (I think it was Angry Louise?) stole all of Santa's presents and now they have to be recovered. The game plays out as a standard platformer; Santa can jump reasonably well for his girth and also tosses short-range magic blasts at enemies. When Santa stumbles across a cup of coffee, however, he turns into Satan temporarily. Well, they call him "the Anti-Claus", but seriously man. There doesn't seem to be much advantage to becoming Satan Claus except that he's invincible and seems to be the only thing that can bring down these big wooden statues that are usually blocking off bonus items; but there's a tradeoff of losing your range weapon and becoming unable to pick up presents.
Every few levels, you put the presents you've collected to good use in a sorta-shooter level where you fly over a major city tossing the presents into chimneys while dodging flying enemies. Strangely you only toss them into chimnies that are smoking, which doesn't seem a great strategy. I dunno what happens to the ones that miss the chimney, either someone is going to be on the phone with the car insurance company or a hobo unexpectedly gets a nice Xmas. Use your imagination I guess.
For such an obscurity this is really surprisingly polished and impressive. Reproduction carts of it abound if you're anti-emulation for some reason; I've seen some claiming to be an authentic release for Australian systems but I still don't know how true that is.