I initially stumbled upon this diamond in the rough thanks to Guerilla Games Nickel City Stories video series. From there I downloaded the free demo rules & played a couple games. We were hooked. The unique activation rules & the Fallout compatible setting were massive draws for me.
The gameplay is quick, gritty, & really requires you to weigh your actions and activations carefully, especially when a model that is hit by ranged fire is still technically "alive" until the end of the turn, more or less. So you have to think "do I want to keep shooting that sniper and make sure she's dead or do I want to risk it & shoot at someone else?". Additionally, the income and exploration is very reminiscent of the best of Necromunda & Mordheim.
The quality of the pdf is very high & professional, you would never know it was such a small operation Joseph has. The artwork in the book is excellent as are the figure spreads. The fact that the game is figure neutral means that even if you don't care for the setting or the fluff you can pretty much adapt the warband and character archetypes to fit any genre or setting. However, Joseph does have some incredidbly detailed and high quality figures designed for TNT. They're a bit reminiscent of the old fun days of gw in terms of the mutants while the humans are very cool and look a lot like NCR Rangers or some badass post-apocalyptic mounties. Also the templates are "universal size" so odds are you may alredy have them anyway.
The fluff is also quite well thought out with the author setting it in & around his home area in order to create a narrative that is unique & interesting. Admittedly myself being a huge fallout junkie I chose to go with that universe for the backstory but even still it does not actually change much about the warbands. Indeed the warbands structures fit extremely well into Fallout as it is.
But, best of all about this: I originally bought the pdf early last year & the rules were updated in Fall/Winter. World's End provided the updated pdf for free. We have all been burned by getting into a game then 6 months later a brand new rulebook comes out & we have to buy everything all over again. Not so with This is Not a Test. In fact, none of the pdfs I bought before the updated rules were even remotely invalidated. I've become a TNT junkie & have everything out for the game yet.
The expansions actually add depth and quality to the game while not unbalancing it. There have been new warbands and characters introduced in the expansions and there isn't the usual "codex creep" that tends to occur with many games where the new stuff is more powerful.
Looking for a good skirmish game? Buy TNT. Like Necromunda & Mordheim? TNT. Fallout junkie? TNT. If you're on the fence watch the vides I mentioned & get the free demo rules. You'll be hooked too.