Battletoads (PC Game Pass) won't let me use an Xbox One controller for player 1

I can't play with second gamepad.

Eore 0xa3ea0066 won't let me istall spore on xbox game pass for PC.

Okay. That makes sense. I can understand that process. How come then my achievements won't activate for Gato Roboto? I am playing Battletoads on Game Pass for PC now and even though that is not a play anywhere title, I am still getting achievements in
that just fine. Is Gato Roboto possibly bugged on PC?

Same here. Plus it took 2 achievements from Bajo-Kazooie: Nuts & Bolts to get me the daily 50.

Am about ready to call it quits, because 1) I do not own any of the other games save for Battletoads and Jurassic World Evolution and am saving my money for certain other games, 2) I've done all I believe I can with Battletoads in earning achievements (only down to 3 - Beating the game on Battletoads difficulty, the 3-player co-op bike challenge, and the -player co-op of beating the one boss without taking damage), and 3) REALLY don't feel like starting new games.

STILL not response from the Support Team, so I am seriously considering throwing in the towel here.

Your understanding is correct. It splits Player 1 so that it is controlled by two controllers.. or as you put it links two controllers so that they were as one. In my case, I have two kids. Rather than ask my kids to pass over the controller I just let
them think they are controlling the character. But I assist them when all else fails. Or I let my two children play as one because I have many single player games in which it could avoid having them fight.

I also left the controller connected to Xbox but it's too far away. I have my Xbox One X downstairs and I have a Windows 10 PC upstairs. The two controllers disconnect due to the long distance away.

I successfully connected my controllers to my Windows 10 PC in copilot mode (to play Windows 10 games). I also successfully connected my controllers to Xbox One X in copilot mode but in direct sync to the console. However, I am not successful in linking
the two controllers in copilot when streaming Xbox One X to my Windows 10 PC. In the last case, my controllers are physically connected to the Windows 10 PC while it is streaming the Xbox One X. The controllers are connected in regular fashion (i.e. they
do work as player 1 + Player 2) in this streaming mode but in configuring for copilot mode or accessories, the streaming does not recognize any controllers despite the controllers functioning as two players. I have tried using USB too to ensure that it's
not the wireless adapter issue. Same result. It might be a situation that isn't anticipated. Nonetheless an issue I stumbled upon as I am avoiding having to relocate my console from downstairs to upstairs. That may be the case if I don't hear any suggestions.

I am not trying to connect the two controllers simultaneously on Windows 10 PC and Xbox One X. Just the copilot mode on Windows 10 PC in streaming Xbox console.