The Deck is truly magical. I suffer to play old games like this on Windows, but SteamOS can handle them just fine.

As said, the game glitches and only plays audio on the right side, but this issue also happens on Windows, and it can be fixed by patching the exe. Other than that, the game has framedrops when there's a lot going on the screen, and for whatever reason stresses the CPU to be at full speed (3.5ghz) even though it shouldn't because it's a retro game, but as I said, it's still very playable and a way better experience than Windows.

Steam defaults to KB&M layout but using a Gamepad layout will correctly map the joystick to movement and all buttons to shoot, which makes it more convenient than emulating either keyboard or mouse, however since ALL buttons are mapped to shoot, you still have to manually set the Start button to Esc if you want to pause the game, other than that, the Gamepad layout works great even for local 3 player coop. Note that you ALSO have to configure the controllers within the game to be Joystick 1, 2 and 3 respectively, and since the game doesn't have Plug & Play capability, you must connect and configure your controllers BEFORE starting the game.

Oh, and since the game res is really low, I highly recommend setting FSR/Sharp to the max, so you can experience the clay graphics as intended.