TL;DR - Avoid at all costs! I'm in too deep but it may not be too late for you.
I've been playing the version on iOS since October last year and a lot has changed. The game deals in ISO and Hero Points. ISO is common but you'll need lots and Hero Points are uncommon but both are required. How much you'll enjoy this game will depend on how much money and time you'll be OK with sinking into this hole.
You collect covers of characters. Each cover is arranged in a 1-4 star configuration. 1* = common, 4* = super rare. How you can get covers is by either winning tournaments or by earning standard or heroic tokens and lucking in to a cover you require. A standard token would typically give you 1* cover with a sprinking of 2* cover and the day you get a 3* cover go get a lotto ticket. Heroic tokens are hard to come across but you can get anywhere up to 19 Heroic Tokens (personal experience) before you get a 3* cover. Why covers of characters and not the characters themselves? Because you can have more than one cover of the same character! Yes! Lazy! For instance, there are 3 covers of Storm - a 1*, 2* and 3* cover. Wolverine has 3 covers - a 2*, 3* and 4*. Thor has 3 covers - 2*, 3* and 4*, etc.
On top of that, most covers have 3 coloured moves and a maximum of 12 covers per chracter. Eg. Iron Man Model 40 (3*) - Unibeam (red), Ballistic Salvo (blue) and Recharge (yellow) (minus Bullseye (2*), Dr Doom (3*), Ragnarok (3*), Loki (3*) who all have 2 moves and a maximum of 10 covers). Meaning in order to max out your character, you need 12 covers and A LOT of ISO to level it up to full level. 1* covers level up to level 40, 2* = level 94, 3* = level 166 and 4* = level 270. Also, each cover takes up 1 roster slot. You can buy more with hero points!
You can buy cover packs with hero points/real money. They come in 1, 10, 42 packs. The amount of REAL money for hero points in this game is highway robbery. There is 0 value. If you were to spend money on this game, it would be in hero points but the little hero points you get for your hard earnt money is not even close to worth it. When you purchase a pack (because the only other time you can earn a 10 pack is through the season rewards), it USED TO guarantee at least one 3* cover. But they took that away because screw consumers. They don't want people having all the good covers by simply getting a "cheap" (it's not cheap) 10 pack with at least one guaranteed 3* cover in it. No no, we want you to jump through hoops to earn that 3* cover! What it DOES guarantee is a higher chance of getting a particular cover! So instead of of chance being 0.8%, it's 5.6%! They are REAL stats pulled right from the game! So if you get a 10 pack, you still have a VERY HIGH CHANCE of getting NO 3* covers! And this game uses them as the highest currency! From the 7 seasons so far, I have had 3 x 10 packs with 0 x 3* covers. This is what we're all aiming for! 3 and 4* covers! You think your hero points cost you a lot? Yes sure, but what are they REALLY worth?!? They can only buy you CHANCES of getting covers! If you already have one colour and you want another, you CAN SPEND 1250 Hero Points per 3* cover.
You have two types of game: PvE (Story) and PvP (tournaments). When you start the game, you can go through the prolog (PvE) which is one of the worst stories ever told. You know that episode of the Simpsons where Burns pulls out the piece of paper from the monkeys typewriter and he reads out, "It was the best of times, it was the BLURST of times?!?" well, that monkey seems more capable of writing a better story than what is present here. Quite honestly, I've stop reading all the "story" in this game months ago as it's merely a flimsy glue that holds this ♥♥♥♥♥♥♥♥ game together.
It's not really pay to win because you can win tournaments (PvP) with a bad roster. The only difference is how active you are in playing. It's a game that masquerades as a casual puzzle game in the vein of bejeweled but make no mistake - they is no puzzle aspect and it's purely a numbers game that forces you to grind and pray that you finish first. All it takes to win is enough time to persist. You can have a strong team and if the computer feels like you're winning too often, it can decide to drop matching gems in favour of the enemy team. I've lost to a team half my level because the tiles dropped in the enemies favour. If you're up against someone who is too hard, you can skip them until you get someone easy. When you lose a round, it really hurts you because you get 5 health packs on a timer - 36 minutes for each health pack. And if you have a limited roster, it shortens the amount of covers you can use in a tournament. Once you've used up all health packs and your covers, you have to wait OR you can buy more health packs. One method of winning is purchasing health packs with real money/hero points and just continue playing until you've earned a score which is hard to beat. Then spend MORE real money/hero points to secure your position with a sheild. You don't really face people in PvP. You face their roster and the computer uses their roster. So how does the computer know which covers to use from other people's roster? Dunno. You would think it would pull their strongest characters but it doesn't always. If you find yourself towards the top of the tournament, you become enemy #1 and your team has a high chance of ending up in other people's list to face. If you don't have a sheild, you can lose points when your team is defeated by others. The only benefit in having the 3 star characters is more people to use in the roster. When your team gets naturally stronger with more 3* characters, you face stronger enemies so your weaker 2* becomes more useless.
Also, it is worth noting that some characters are USELESS such as Bagman Spiderman and Bullseye. Bagman Spiderman has 3 useless moves, each more usless than the next and Bullseye is a 2* with 2 moves which means his max level is 78. And while he can lay down defense tiles like crazy, he can't take a hit which makes him pretty useless. All your 1* covers are useless 99% of the time once you develop an even remotely strong team.
Why it's not really pay to win as well is because this game has no end to it. The end is you have all the covers. And they continually release new characters so the end to this game is when they shut down the servers or stop releasing new characters. It also feels like they do very little testing with the new characters/covers they release. We see it often when a new character comes out. It's hard to get excited about it when we know the second a bunch of people flock to the new character, it means its overpowered and will be nerfed.
Also, saving is a little ♥♥♥♥. If you want to save your progress, it is only possible through Facebook connect on iOS. I didn't see any feature on PC and I don't know what Android saving is like.
If you hate your life and after reading what I've had to say still want to go through with your cult suicide
decision to play the game, go join an alliance. They now cost nothing and the benefits are huge. Although you need to accept that your alliance will never be in the top 10 unless you have contacts and join one of the already established X-Men groups who are always in the top 10. Hell, it's hard to even place top 100 alliance without all 20 players being dedicated to winning.
In over a year, I've had to step back from the game 3 times because it has made me that angry and upset. I now play on a very casual basis and I can only ever treat it like that otherwise you burn out. I loved Puzzle Quest 1, 2 and to a degree, galactrix. But this is just dead ♥♥♥♥.