Ranked in these QuestionsQuestion Ranking
Pro Low system requirements
A machine with a 2GHz i3 CPU and 2GB of RAM can run the game.
Con Doesn't represent the arena shooter genre properly
It's as much arena shooter as "catch-ball" is baseball. In catch ball your only focus is to throw and catch the ball, similarly in RatZ instagib your only focus is in one weapon, aim and dodging. That is to summarize the complexity of the game excluding additional gameplay elements included in game modes like capture the flag and freeze tag.
Con Doesn't deliver anything new
It's like a poor clone of Xonotic's Instagib. Instagib in any shape and form exists in almost every arena shooter already, it's also done better in most of them. Some of them (Xonotic) are free and has 100x times the content.