Pyross is a cancelled action platformer based on the original Wardner / Pyros arcade game, which would have been published by American Sammy Corporation for the NES. While a 8-Bit version of Wardner was released for the Famicom Disk System in Japan, it was a different game from this canned one. Pyross was shown a few times in gaming magazines previews (such as in EGM 13), its american box-art was already designed and they even had an advertisement flyer ready, but in the end the game just vanished forever:
“Princess Pudding has been captured, and it’s up to the dashing prince to rescue her. But this is no mere walk in the woods! He must challenge hordes of vile creatures, avoid deadly traps, and master the weapons of fire before time runs out! Shall the beloved princess be crystalized by the forces of darkness, or will Ala Mode make things too hot for evil to handle?”
We can only hope one day a prototype of this canned NES version of Pyross could be found by someone and preserved online.