This game is sooo good. I can't believe that after it's first reveal I was skeptical that a sequel to ALTTP could work. I have one dungeon left and the final castle and don't want it to end. The dungeons and puzzles are incredible. They may be small but there is no pointless rooms, with almost all of them containing some form of puzzle and purpose. Some reviewers noted that the bosses weren't great but I disagree. Maybe compared to 3D Zelda titles but the bosses are great for 2D Zelda, much better than ALTTP.
The renting system is a little bit of downside to me. I understand it's purpose is to free up the game. Allowing for a more open ended approach to dungeons but perhaps a better alternative would be mini dungeons specifically for items.
I think the game overall is fantastic.
The freeflow dungeon order is great, and the rental system is sort of a necessity for it. My concern that it would ruin the feel of progression of your character turned out to be unfounded, as the upgrade system as well as items in the dungeons made up for it (really, the tools were taken out of the dungeons and the character upgrades put into them).
However, I do feel a sort of restriction on the rentals, at least early game would've helped add a strategic element to usign the items, just to prevent you from just getting everything early on at once.
For example:
1) Have each item cost more to rent if you are already renting some. Like the first item you rent is 20 rupees, and the next 40, 80, 160, 320, 640, 1280, and the last one 2560.
2) maybe allow only 3 items at the beginning, so you have to choose which you want to go out with, and have an upgrade (or two) to eventually allow you to carry all at once.
3) maybe both of the above.
Anyway, it's still good. I think the game is great, as it really is a new style of zelda, 2D, but sort of 3D as well due to the wall mechanic and levels.
I thought it relied a little TOO much on lttp, as it's nearly a pseudo remake. It's probably a better game overall than lttp, but lttp is a product of its time, and a more perfect example of this type of game, whereas lbw has a few faults.
I just replayed lttp on gba, and I surprised myself at how fast that game is as well. I finished some of the dungeons in 15 minutes! (dark world ones too!), on average, those dungeons were 20-30 minutes if you've played them before (I remember them, but forgot details so was still playing them through, not speed run style).