Yeah, it's totally free. No ads, iaps, or anything. it's a "set completion" card game, where you play the different types of weapons in front of you, and you can play multiples of each weapon, up to three. The more of each weapon you have, the more damage it does when you attack with it, up to three, when it is now considered a "super weapon." Super weapons do the most damage, and are also safe from being stolen with the normal weapon stealing cards. But there are several cards than can steal a whole super weapon. They are also the goal of the game. You set how many super weapons you need to complete to win the game in the settings menu.
Another kind of cards you can play in front of you are minion cards. They are a kind of "currency" card that you can pay when attacked instead of losing weapons. Also, your character card can spend minions to activate their special ability. So you always want to have alot of minions handy.
Attack cards list two of the weapon types, and you play an attack card, then specify which weapon you are attacking with and who you are attacking. The strength of the attack depends on how many of that weapon you have. The defending player has to give minions equal to the attack value, and if they run out of minions, they have to pay the difference in weapons.
There are other special cards that have various effects in the game, but those are the basics. Having played a few rounds and described the basics above, I have come to realize that this game is almost a card for card reskin of the "Monopoly Deal" card came. That's not a bad thing, because I have that game and it is alot of fun. But they have replaced the cash with minions, the properties with weapons, and the "landing on property" cards with attacks. So if you like this and want a physical version, you know what to get, lol.