The level packs are nice, but over-priced except on sale. I haven't played them all (just ordered the last two, Ghostbusters and Dr. Who), but Portal is a must get, and Midway (especially if you like classic arcade games, it has about 20 emulated games included on top of the level, but you do have to have other level packs to get them all - like Simpsons for Cyberball).
The game is similar to other Lego games, and each figure from a different franchise unlocks a hub world attached to the main hub world with more stuff to do. There is a list floating around of minimum purchases to see 100%. Each figure has certain abilities (like with other Lego games), so you have to have a certain collection of them to do everything.
Yes, there is a paywall on figures unlike older Lego games, but you do get some spiffy Legos (not too out of line with small pack purchases, especially with these deals). But unlocking hub worlds for franchises adds to the value.
And one nice thing is the main starter is getting new content all the way through next year with no new base game. They have at least a couple new full fledged "Story Packs" that come with Legos to alter the appearance of your portal, multiple new levels (6 per), and figure/items. So far I know of Fantastic Beasts and Ghostbusters 2016 for those.
Personally, I altered the build of the original portal anyways because it had too many things sticking out that made it hard to store when not playing. The big loop thingy is just a pain as well as many of the little hanging stuff that constantly come off. Build it once, then take it apart and make it something you like with the pieces (or add some of your own). The portal itself works fine with no Legos attached, it is just a base with studs for attaching other Legos.
