This opening is playable but static and inflexible, there are better openings available. (Nimzo-Indian, Queens-Indian, Bogo-Indian etc)
This is the Modern Stonewall Dutch (1.d4 f5 2.g3 Nf6 3.Bg2 e6 4.c4 d5 5.Nf3 c6). It is a proven durable and solid defense played by Grandmasters as well.
Black's plan is to activate the dead bishop at c8. After castling he can play it to h5 via Bd7, Be8, Bh5 and then trade it off for a knight or bishop if possible.
Make sure you understand and memorize the Black Setup. You can play this setup even if White plays other things like 1.b3 or 1.Nf3.Get Books / Modern Stonewall Dutch - Click here!
Replay the games and watch what Black does with his dead bishop. It is important that you handle your white c8-bishop correctly or you will have a dead bishop in the endgame and lose...