Even if you panic, you most likely not going to die.
It uses the same principals of tetris, eliminate the elements before they reach the top of the screen. There are five rows where you can controll the position of the blocks that have lines in it, and to eliminate the lines you need to link them on all rows and can perform combos by creating complex line arrangements. One big problem I had was the difficulty and the way the elimination works. On tetris for instance, if you panic, you're not going to get far when you just start button maching, but in Gunpay almost every time it was connecting the blocks and eliminating them, to the point that it made the game quite easy and pointless.
I believe I played the total ammount of one hour, beat the game a few times and I don't believe I'll be coming back. So only if you find this game for a couple of bucks I'll be able to recommend it. It's a short, very short ride.