The Xperia Play is notorious for its specific hardware drivers (particularly the GPU and the slide-out gamepad) and the complexity of its partition layout. Users frequently "brick" their devices or lose functionality (camera, touchpads, or GPU acceleration) because they flashed a ROM with an incompatible baseband, an incorrect kernel, or the wrong GPU firmware.
Even with the best Xperia Play custom ROM, you may hit snags. Here is the fix for the top three complaints: xperia play custom rom