Fish in a Barrel Trophy / Achievement of the newly released Resident Evil Revelations 2 will give you one Bronze trophy or 20 Gamerscore points depending upon your console. To get this Trophy / Achievement all you have to do is, in the main campaign kill five enemies with the use of one exploding bottle or firebomb bottle.
You will get a good chance of getting this Trophy / Achievement while completing the "Escape from the facility" from the first chapter. You will find a bottle of explosive when you look for a key.
When you open a locked door using the key that you just found, you will have opened a room full of dangerous bugs and spiders. Quickly reach the middle of this room and throw the explosive bottle to kill many of these bugs. Try to be quicker than your teammates.
Watch the following video on how to get Resident Evil Revelations 2 Fish in a Barrel trophy / achievement.