If you enjoyed the Young Justice TV series, then this game was something that you were probably looking forward to greatly, and something which we had all hoped would tie together different aspects of the show. The game is meant to take place in the years between Season 1 and 2 of the TV series, and is meant to fill in a lot of the gaps that happen in between these points. I wont go into spoilers, but the game does cover some of the aspects that weren't explained in Season 2, with a reasonable explination as to the events. That, really, would be the only reason to purchase this game, but I'd highly reccomend you just find a Let's Play and learn the story that way.
The gameplay at release was quite glitched, with the multiplayer feature not even working out of the box, and because of that, there is a lot of trouble finding a co-op game. If you're lucky and have a friend that can play it, then you're fine as you can play together - unless you have a network card that doesn't support each other, according to the Developer's posts on the Steam forum. That's okay though... except that Single player also has a lot of issues. Firstly, they never explain the controls to you in any meaninful way if you use a gamepad - and you'll want to use a gamepad - so you spend a bit of time figuring out how to even do certain moves, such as your heroes/heroines special attacks, or the Sqaud move, for the group or single. On top of that issue, there are various crash reports that are visible from the forum; I myself have the game crash when I attempt to go to the challenges section, and if I press B during hero select on Multiplayer, it crashed the game entirely. The Developer hasn't released any content for this game since they "fixed" multiplayer - which took almost 2 weeks after release to even comment - and has not made their presence known on the support forums either, making it appear that this game is all but dead to them.
Combat in the game tends to get a little repative, as there is little challenge in it across the entire game, and boss battles are rarely a challenge even on hard. Whereas it had a chance to create something amazing with an entire catalog of DC powers to come from, Superboy, just seems EXTREMELY underwhelming in attack power, and hits just as hard as Miss Martian, who the game states is physicall weak. There seems to be very little balance between the heros, with many of the feeling the same, and the ones that do feel special, they become your go to heroes because they are so over powered compared to the others. For example, one Hero gets a heal that impacts an circle AOE, and you need to be in that AOE. The next healer you get, impacts EVERY hero on the map, no matter where they are, and heals for a far greater amount, making the first hero almost meaningless to play as.
This game, really, lacks any real gameplay, or even more important, game stability. Unless you were a big fan of the TV serieds and want to support that, then I wouldn't bother getting this game. Read up on what the story is, watch playthroughts of it, or something to that extent, because even if this game hits $10, there are far superrior titles with less bugs even at that price range.