At first I was looking at the price and thinking dammit this is bad then Im out three dollars. This game honestly should cost five dollars for how good it is. Very reminiscent of breakout but in three dimensions. Simple yet very effective graphics and art style add to the game and fit the atmosphere very well. Just in World War I I played about 15 to 20 missions I forget and at the end of every world there are boss battles. On top of all of that the button for your cardboard activates slow motion for when the game gets really hectic, oh and it does get hectic. I played for a good 15 minutes and didnt have any issues with eyestrain or sickness of any sort. For a iPhone game this is fantastic and highly, highly, highly recommend picking it up.
Roash about Proton Pulse for Google Cardboard