Take one of the most modern, fun and engaging board games created in recent years. Match it with cutting-edge technology. Add a ridiculously well-crafted art style and a ton of extra content. This is the recipe to one of the most thrilling, charming and captivating strategy games you will ever find!
Yes, you're right: at the moment the game doesn't allow you to throw grenades out of windows/doors (you can throw them out of fortified positions, though).
I added this to our to-do list. We're always working on getting the rules more compliant to the board game (in the next patch we'll introduce kill shots, and correct the opportunity fire calculations, for example). We'll definitely implement grenades-out-of-buildings too, in the future.