There have been many Lego games based of movies and super heroes, Lego Avengers is the second game in the Marvel series to be getting the treatment in video games. The last Lego game we saw was back in 2013 with Lego Marvel Super Heroes, Lego Avengers is based on both The Avengers and Avengers: Age of Ultron however in the Vita version of the game only covers both films on story. Unlike the console versions you'll get more content including the DLC, in the Vita version it doesn't have any levels that were used in Iron Man 3, both Captain America movies and Thor: Dark World. But you still get a really good experience in the handheld version especially the PS Vita version of Lego Avengers, I was surprised at first on how much detail had gone into this especially the movie cutscenes which look nearly good as the consoles version they really do look impressive to look at and close to both films itself.
Another feature you will certainly notice is that you'll have the freedom to do whatever you like on the streets of Manhattan filled with landmarks and skyscrapers you can easily cause destruction as the Hulk or easily fly around the city as Iron Man, you would expect something like a Grand Theft Auto style game to be added in but it’s not as easy as you think consecutive decisions had to be made when it came to developing and releasing this on to the PS Vita. You may suspect some lack of detail and some long loading times but they can easily be ignored after easily getting distracted by going through the main story, there are side-missions which can do at any time when you are in Manhattan or on the Helicarrier including missions like causing destruction and getting a high score within a time limit or getting the fastest time under 2 minutes by running or flying through purple spheres.
Like past Lego games where you have to go to a shop in order to buy other characters and red bricks which are cheats that you can use in the game, you can easily do all of that by holding down triangle while choosing an Avenger you want to play as you can access the unlocked character tokens you've picked up during the main story or completing a side-mission you can purchase them and then are unlockable to play. For the red bricks you can easily pause the game and head over to red bricks you can purchase the cheats you want and easily turn them on or off at any time but the in order to get those cheats you'll need to find them which are scatted in each level during the main story in both Avenger movies. You can build stuff by holding down the circle button to build new objects or complete certain puzzles. If you press triangle you can switch characters and during the main story you can switch back and forth on various characters based on the main story. With 15 levels to clear through on its main story it shouldn't take you that long to complete at least a good 5 hours in total it however you'll be going back and forth levels to pick certain pieces and collecting studs.
There isn't 2 play co-op meaning that you can't play with a friend, but if you have PlayStation TV this game is compatible if you want to play the PS Vita version on a bigger screen. You can also use the touch pad for playing the game but it feel really awkward so you might want to stay away from the touch controls but the whole game itself plays really well. The movie soundtrack makes a great touch too including the graphics and visuals, there's quite a few funny moments where certain stuff that were in the films but are replaced with silly Lego objects.
Trying to gain 100% shouldn't take you that long I would guess around at least 20 or less depending on how much you get through it or how much fun you want out of a Lego game. If you have a PS Vita I would recommend having a look if you really want a good experience of out a Lego game and a game on the go I would say yes but if you have console in your home you are better off picking it up if you want the full Marvel experience.