You'll have more fun remembering the game than actually playing it.
In Turtles you get very few play modes. There is Story mode that is 4 players online and off, a Quickplay mode that lets you skip to any level you've already played through, and one other mode called Survival were you only have 1 life and when you die it's game over. All of these modes have the same 4 difficulty levels to choose from. The online works well enough and it handles lag very well. You won't experience any slow down but the players on the screen will jolt around if your connection can't keep up.
Whether or not the gameplay is good is really a matter of personal opinion. If you still enjoy old school beat em' ups that are all about holding Right and wailing on the X button then this game is for you. If you've since abandoned that style of gameplay and can't find yourself getting back into it then this game won't win you over. All the turtles play exactly the same other than some characters having further reach with their attacks, like Donatello and his bow staff, or some moving faster than others. But no matter what Turtle you pick your game experience will remain the same. You can also now attack in all 8 directions instead of just in front of you and behind you and this makes the game a lot easier than it previously was.
If your someone who never played the arcade version but instead played the SNES version then this isn't the game you remember. This is the arcade version remade. That means you don't get a Technodrome level and Shredder instead transports you back in time at the end of the 3rd level where you're in the sewer fighting the yellow Alien lookalike monsters. The prehistoric level does not have the evil spiked turtle as a boss but instead has a mud monster for the boss. Also in the pirate ship level you fight Toka and Razar instead of a pirate Beebop and Rocksteady. So this is a fairly different game than the SNES version and you should keep this in mind before paying for a copy.
So for $10 you get a very outdated game that probably isn't the version you remember. On top of that you can beat the game in about 30 minutes and if you know what your doing you can get most of the achievements in one play through. You also can't switch the graphics back to the classic look so your stuck with the updated look. Buying the game is just a matter of whether or not you want to play an outdated beat em' up.