So sad pc-engine version of Forgotten Worlds is only 1 player. Graphically it's pretty much up there with the arcade (minus the parallax), and has all the levels. Not to mention the music and the arcade plus pc-engine voices for the cutscenes.
Why do they make known 2-player arcade games single player on consoles? Laziness or sprite limits?
It's a combination of lack of skill or effort when dealing with sprite limits. Most developers seemed to only know how to do so many things and were completely oblivious to certain tricks. This is why too many PCE games have static backgrounds with tiles lined up perfectly for h-sync parallax. Many developers who turned out impressive ports like Forgotton Worlds were still very sloppy with sprite usage. Forgotten Worlds for PCE already has less screen coverage with sprites due to using the medium resolution, but Tomaitheous looked into the game and found, like too many PCE ports such as Tenchi Wo Kurau, that sprite sizes were inefficient. It's amazing that the game doesn't have more break-up/flicker.
I think that Sidearms uses sprites for the better-than-arcade parallax. Even though it also runs in medium res, I think that 2-player gameplay would be fine, with an acceptible level of sprite break-up. The programmer likely wanted to shoot for as little as possible. All the PCE games that fill the screen with sprites, especially those 2-player shooters that have to plan on players flying and shooting anywhere they want, prove what can really be done. That's one of the most impressive things about Sapphire. Even if any one person doesn't appreciate the art style, animation, gameplay, etc, -it's still filling the screen with player ships with two options each, all firing huge ammo, going up against tons of enemies with bullets and giant bosses with long segmented limbs, who fire giant ammo as well... with sprites in the background for extra parallax/decoration.
