Well, I came up with what I think the levels will be yesterday, so I might as well repeat them here. SPOILERS. This is assuming TFA only has 6 levels.

Level 1: Prologue Part 1: Play as Poe and BB8, until Poe is captured. Part 2: BB8 finds rey and they leave the Star Destroyer ruin

Level 2: Escape from Jakku Part 1: Get Finn and Poe to the TIE Fighter Part 2: Use the new dogfight mechanic until something happens. Part 3: Get Finn and Rey to the falcon

Level 3: The Falcon Part 1: Fly the Falcon through the Graveyard of Giants. Part 2: Defeat the Rathtars

Level 4: The Battle of Takodana Part 1: Rey and BB8 Go through the Forest, and Rey gets captured. Part 2: Finn, Han, and Chewie fight Stormtroopers and stuff. Part 3: X-Wing Dogfighting above the castle.

Level 5: Attack on Starkiller Base Part 1: Poe, Han, and Chewie find Rey Part 2: X-Wing Dogfighting Part 3: Poe, Rey, Han, and Chewie encounter Kylo Ren and there is a short boss fight. RIP Han.

Level 6: Destruction of Starkiller Base Part 1: X-Wing Dogfighting and Blowing stuff up. Part 2: Big Kylo Ren Boss fight with Rey and Finn. Part 3 (?): Rey and BB8 find Luke.

And that's what I think they will do. The formatting on Wikia sucks, so sadly I don't know how to make this look better.

I was thinking about the same thing. But realize that's only 6/15 minimum...how many levels could we possibly be getting from the in between 6 and 7 plot? There must be more...