Yes, I have pywin32 installed, as far as I can tell PyInstaller installed without any warning messages. It is giving me the executable, but when I click on it I get the error:

"Fatal Error! Failed to execute script pig"

I also noticed that the pygame window is opening, but when I click OK in the Fatal Error dialog, the pygame window disappears.

After looking through the build time messages, these are the only messages that stand out to me to be possibly problematic.

...
1450 INFO: UPX is not available.
1450 INFO: Extending PYTHONPATH with paths
...
24738 WARNING: Hidden import "pygame._view" not found!
...
27438 WARNING: library loader required via ctypes not found

So, I recompiled my game, and left out the --windowed argument. When I ran the executable in the command prompt I realized my first problem was that I needed to make sure my sounds were in the same directory as the executable, oops. Second problem was the error:

Traceback (most recent call last):
  File "pig.py", line 217, in <module>
  File "pig.py", line 28, in main
  File "accessible_output2\outputs\auto.py", line 12, in __init__
  File "accessible_output2\outputs\base.py", line 19, in __init__
  File "accessible_output2\__init__.py", line 15, in load_library
  File "ctypes\__init__.py", line 426, in __getitem__
  File "ctypes\__init__.py", line 421, in __getattr__
  File "site-packages\PyInstaller\loader\pyiboot01_bootstrap.py", line 152, in _
_init__
  File "ctypes\__init__.py", line 351, in __init__
OSError: [WinError 126] The specified module could not be found
Failed to execute script pig

Okay, so I did some testing, I tried copying over the
nvdaControllerClient32.dll
file into my programs directory, it did not work. I tried compiling it as a single directory rather than a single file and it actually worked once I dropped in my sound folders without the NVDA dll. I would still like to try and make it work with a single executable though. So, I traced the error message myself, and noticed a message underneath the message about base.py.

  File "accessible_output2\__init__.py", line 15, in load_library

I found that file and it looks like line 15 is refering to say.py, which is for voice over.

I would rather not use py2exe if I can avoid it just simply so that I can build a one file executable and not have to deal with all of the files.

Bump. Well I managed to get accessible_output2 working in a single binary with pyinstaller, though i'm not sure if this may be the same issue you've had. The problem had to do with accessible_output2/__init__.py load_library(). Basically its hardcoded to search in "your-binary-directory/accessible_output2/lib/", I tested it and if you build as one file and drop the accessible_output2 folder next to the binary it works fine. It breaks when I tried packing the dll's with the exe though because when I run it, all the resources are unpacked to a temporary _MEI folder on C drive, and AO2 can't find them then because its hardcoded to look in the compiled binaries working folder. So, I made these changes to accessible_output2/ __init__.py:

def load_library(libname, cdll=False):
    if paths.is_frozen():
        libfile = os.path.join(paths.embedded_data_path(), 'accessible_output2', 'lib', libname)
    else:
        libfile = os.path.join(paths.module_path(), 'lib', libname)
    if cdll:
                try:
                        return ctypes.cdll[libfile]
                except:
                        libfile = resource_path(libname)
                        return ctypes.cdll[libfile]
    else:
                try:
                        return ctypes.windll[libfile]
                except:
                        libfile = resource_path(libname)
                        return ctypes.windll[libfile]

def resource_path(relative_path):
    """ Get absolute path to resource, works for dev and for PyInstaller """
    if hasattr(sys, '_MEIPASS'):
        return os.path.join(sys._MEIPASS, relative_path)

    return os.path.join(os.path.abspath("."), relative_path)

After that just add the dlls to the spec file as regular data files like so:

a.datas += [('dolapi.dll','D:\\compile\\dolapi.dll','DATA'),('nvdaControllerClient32.dll','D:\\compile\\nvdaControllerClient32.dll','DATA'),('PCTKUSR.dll','D:\\compile\\PCTKUSR.dll','DATA'),('PCTKUSR64.dll','D:\\compile\\PCTKUSR64.dll','DATA'),('SAAPI32.dll','D:\\compile\\SAAPI32.dll','DATA')]

During tests the sapi5 driver didn't do anything though, but the NVDA driver worked fine.