Although they are working to improve it (apparently in this very version), the beginning is a bit tedious.

There are two "open zones" now in the game, which are like your average MMO: "talk to this guy", "kill 10 things" kind of quests.
To be honest, while the new zone is more interesting, it remains uninteresting, and boring. The game is designed to be played in team, not alone.

If you let aside these open zones, you will find "missions":

- Mercenary is PvP. 12 vs 12 players, in missions which are like most team shooters: capture the points and hold them, payload, etc. Not my preferred mode, but it's nicely done enough.
- Spec ops are PvE mission. You embark with 3 teammates for a map to travel through, killing enemies, up to killing a boss at the end. These missions, at least when you reach high difficulties, are really tight, requiring good teamwork.

You have 4 classes in this game, and they work well together:
- the Assault, the local heavy/tank, with a machine gun and a big armor
- the Medic, in charge of keeping the assault alive, and occasionally the other members
- the Recon, the DPS with a sniper rifle, but also group damage with bombs (really helpful in Spec Ops to not be overwhelmed)
- the Robo, the local engineer, building stations to regen health and power, as well as turrets.

In the higher spec ops, you really need a good teamwork to go to the end, with everyone doing their part. It feels great in this matter.
Mercenary can feel great for the same reasons, but it's often messy, and with people doing their own things, as you can expect in a multiplayer shooter.

On top of that, in MMO components, you have levelling (used to unlock skill points, up to level 30, and to access higher spec ops zones), items dropping at the end of missions (individual and random), and crafting, though this one is optional, as it doesn't give a major gameplay advantage. It's good to have better items, but it's not gamebreaking to not have, you won't get torned off just because of a difference of "stuff".
It mostly depends on how well you play as a team.