It's been a long time since I felt addicted to a game, but this one turned out to be quite a surprise.
First impression was bad. It's well known that "button-mashing" is one of the sins of game development, and only poor developers use it. Fortunately, button smashing is mostly optional in this game. You see, as soon you have some money in hand, you can (and should) unlock the Archer and upgrade it, so you don't have ruin your fingers (or your mouse) with all the fighting.
Upgrading your own character is still a good idea, if nothing else, to increase his health, just in case the opponents get a hit or two in, before they croak.
The Monk, however, is mostly underpowered. He's useful with his heals, buffs and debuffs, but you can live without him. He would be more useful if he had some more useful abilities, like increasing money drops, or an attack of his own. Pity.
The game covers four time periods, Feudal Japan, Middle Ages, US Cowboys and Space Robots (or something along those lines). Each period has a sequence of levels, some of which have bosses in them. Bosses have longer life bars and hit a bit harder, but they also drop more money, so they're ideal for farming.
Once you beat the last level of the Robot period, that's it, which is sad because I'd like to try and unlock some more upgrades for the characters, but I had no choice to do so.
Speaking of which, the upgrades are a great idea. Too bad there's an emphasis on quantity over quality. Most of them are just a +# to this or a +#% to that, and you'll probably never unlock all of them because their cost is exponential, which means the later ones are insanely expensive - plus, you don't need them to beat the game, which begs the question, why are they even there if they're not needed and they're so hard to get?
The last down side I'd like to point out is that there's only one music for the whole game. The music is good, but it gets repetitive, and some variety (at least one different music per time period) would have been nice. Fortunately, you can mute it, a feature too many game developers here on Newgrounds seem to forget.
All in all, one of the best new entries I've seen and played, but could use some polish and improvements.