It's always been a free download, but pay-to-customize.
I think they started something much like Infinite Crisis where every few weeks, they spotlight a certain character. See, the base game only lets you play as one character, but they spotlight a new character sometimes so you can play as that character instead.
Even if you buy the game, though, it's a great value. Each character is $4.99, there are going to be 8 characters in-total... and to buy the full game you can either buy the $19.99 Combo Breaker edition, which unlocks all the characters for you... or you can get the $39.99 Ultra edition which comes with all the characters, all customization items, and the original arcade version of the first game in the series.
To add to the previous post, if you end up buying a few characters then decide to buy the Utra Edition you will never pay more than 39.99 total.
Another season is coming at the end of the year which will be a payed add-on including new characters, stages and more.
Wait so if I buy 7 characters for $5 each and then decide to buy the Ultra edition, its going to cost me only $5 extra? --- GT: DeadLock25 FC: 0232-8879-2244 || Pkmn Y IGN: Pasha || TSV: 2535 ||Friend Safari: Ghost: Phantump, Golurk, Lampent
Not right now, but the arcade mode will be added in this month I think.
It's Pay 2 Win, as you're going to either buy characters or not play.
It's not pay-to-win. You can master Jago as the sole character in the game. You don't have to buy upgrades or anything... generally pay-to-win denotes a game that makes you pay for advantages. Killer Instinct doesn't make you pay for advantages, just options.