Destiny 2 has you in control of one of three Guardian classes (Titan, Hunter, Warlock), and you are the last protectors of Earth. Different alien species have invaded, with one in particular wreaking havoc by stealing the Light of the Guardians. It is up to you to travel to different areas, including different planets, to regain the Light (also referred to as "Power" in
Destiny 2). The main antagonists in the story are the Cabal, with their leader, Dominus Ghaul, charging the way for destruction.
Destiny 2 is built on the backbone of its predecessor, Destiny. Like the first foray, the gameplay elements in this second outing heavily revolve around leveling up your character to help progress, but even more importantly, leveling up your armor, weaponry, and Light. Your character will max out at Level 20, but loot and power will continue to flow. Bungie has apparently upped the quality of the mission-based portion of Destiny 2, however, and I can speak to the story being relatively interesting, although short in the grand scheme of things. [Disclaimer: I had only previously played Destiny for an hour or two via rental, so have researched the differences online as well.]
Campaign missions will have you jumping from planet to planet and can quickly get your adrenaline flowing. That is probably what I enjoyed most about Destiny. Sure, there is the (limited) social aspect of the always-online persistent world where you can see and join other players in the same game, but I truly enjoy the single player aspect as well. Alien waves continue to come when you get to certain areas, and respawning is limited in scope in others, which drives the difficulty even further. There are a lot of intense moments that will certainly keep your heart pounding.
Destiny 2 does, however, rely heavily on the multiplayer aspect to keep gamers coming back. There are cooperative and competitive modes that include players joining forces in Events, Strikes, and Raids, as well as Player vs Player 4-on-4 matches, respectively. Because Destiny 2 requires a whole lot of powering up, however, be ready for the game to suck a whole lot of hours of your life.