Basically, this is all back story. And after the mess of TRON:L I didn't expect much. But I was pleasantly surprised. This movie might be light and entertaining, but compared to all other similar movies it had surprising depth and I didn't felt (too) dumb while watching it. I somehow felt that the actors were more closely focused on delivering the physical aspects of their parts, but Fassbender and the direction somehow managed to make some rather preposterous scenes watchable, even enjoyable. Best example for this was the radar telekinetic test - this scene could have been cringeworthy, but they somehow managed to hold it together within the limits of such a film.
The ending felt a bit forced with the extremely stagelike showdown on the beach, where quite a lot of characters undergo some rather sudden changes in policy. Maybe they stretched it just a little bit there.
Study the satellite dish scene, for not being cringe worthy.