I don't like TextBox, it's ugly (for games), impractical, hard to customize.
If I needed a simple text input for my game, I would probably make my own custom "textbox" using Text or SpriteFont object.
Shouldn't be too hard - read keyboard input to add or remove characters. Use symbol "|" for cursor, blink it every second (replace with " "), move cursor with arrow keys.
Setting cursor to mouse position could be tricky, but still possible with SpriteFont as you can get the exact size of each character.
Of course if you need text selection, copy-paste functions - this will require more effort.