The code can be re-written simpler:

import pywinauto

app = pywinauto.application.Application().connect(title_re='Form1')
Form1 = app.Window_(title_re='Form1', class_name='WindowsForms10.Window.8.app.0.2bf8098_r13_ad1')
Form1.SetFocus()
Form1.TypeKeys("{PAUSE 2}")
Form1.TypeKeys("{TAB 2}{PAUSE 2}{ENTER}")

TypeKeys automatically sets a focus to the Form1 and types the keys. SendKeys doesn't set a focus because it's not aware about the window. That's probably why it doesn't work with SendKeys.

[EDIT] Of course you need to run the script as Administrator.

Just use

# from pywinauto.SendKeysCtypes import SendKeys # old for pywinauto==0.5.x
from pywinauto.keyboard import send_keys

send_keys('some text{ENTER 2}some more textt{BACKSPACE}', with_spaces=True)

Docs: https://pywinauto.readthedocs.io/en/latest/code/pywinauto.keyboard.html

P.S. SendKeysCtypes was renamed to keyboard in pywinauto 0.6.0+.

There are few moments. If the game process has its own window with native handle, you may try the following:

 app.window(title="Window title").send_keystrokes("something")
 app.window(title="Window title").send_chars("something")

It should work even for minimized window. The difference may appear for special symbols which may not work for some of these methods or even for both. But arrows should probably work with send_keystrokes.

If it's DirectX game, sending keys might be more complicated task. A while ago I found some references about potential implementation of this: https://github.com/pywinauto/pywinauto/issues/469 Though I had no chance to try it yet.

For the specified UI element this method is

# it will activate target window if it's not in focus
ditto.ditto.SysListView321.type_keys('^e')

but

keyboard.SendKeys('^e') # should work also if you don't change active window

It can be used without binding to any specific control.

So you shouldn't try using module name (like keyboard) as an attribute name of any object. It's Python. Just learn Python basics and you will understand pywinauto better as well.