I've been playing Median in 2D for years

Is it possible to make the window with Glide bigger? When I try to maximize it I have just a small game window in left corner.

Are you using the launcher? If yes, try checking and unchecking the "window mode" box everytime you start the game via launcher again.

I use glide and don't play in windowed mode.

Oh okay, you need to change Glide settings in D2SE to maximize the windowed mode. You have different resolutions there.

(just for future questions)