Right out of the gate Gentlemen
boxes itself in a corner. A local multiplayer only brawler, it requires a group (preferably of four) to crowd around the computer to even be able to play the game, which obviously alienates a good chunk of potential players. Assuming you can round up some friends however it's hard to imagine spending much time with these dapper little maniacs, as the amount of content is nowhere near enough to sustain more than a handful of minutes of play, and with the work some will likely have to do to get enough players I couldn't recommend it over any one of the many more compelling options available.
Gameplay falls somewhere between Super Smash Bros. and VVVVV, as you flip your way around the arenas collection weapons and trying to rack up the requisite number of kills first. That's really all there is to the game, as options are barebones and the different modes do little to switch up the experience (most do nothing but change which weapons are available to use). All of the gentlemen and ladies play the same and are just cosmetically different to be distinguishable from one another amid the chaos of everyone jumping and shooting at once.
Truth be told I did actually have some fun do to the inherent insanity that breeds a certain level of comedy when no one understands what happened, but it was very short lived and considering both the price and prerequisite of gathering and keeping entertained several other people to play, I cannot advise others pick it up. Were the price significantly lower it would be a harder call, but at $10 with only about a dozen arenas, simply drawn and repetitive artwork (one character is barely more than a color swap), and gameplay that looses its charm after
you learn how to play, I can't see anyone getting their moneys worth out of Gentlemen!
Nine out of ten suave tea drinking gents agree it's not worth it.