oh wow, at first I'm quite bored with episode 4, thinking that it's just the love development between Ohno and Tanaka as seen previously in the manga; but later it turned out to be something we never seen in the manga. Poor Tanaka for being cornered to play the eroge (10 straight hours? oh my, spare me). The ending part certainly is nice, seeing Ohno turned up cosplaying as the eroge character.
Overall this is another good episode to watch, but certainly I'm eager for episode 5 after watching the preview: