I think half the problem is that everyone is constantly comparing this to the animated version which does make sense I guess.
However it is still a great film, has amazing visuals and the voice acting is spot on. But with praise there will always be negativity, and for me the problem was that they seemed to rush through the film; even though its basically 2 hours long it felt like they crammed it all together. The most important and emotional scenes didn't last very long and that's quite disappointing as they should've made them the main focus. Some of the most inspiring lines also got delivered poorly and it takes the gripping feeling away.
Still that could be me being picky as I am a religious watcher of the animated original.
What I liked was they added some more aspects to the film that was not in the animated version and to be honest it made it better, it also made more sense to have these differences.
I was happy with all the voices, although not quite as great as the original each character sounded good, especially for me zarzu who was very convincing, pumba and temone(sorry about spelling?) had tremendous chemistry and for scar, well although not as iconic, the voice was still fitting for this character and was pulled off to almost perfection. Mufasa did sound quite old an lost some of his power in the vocals but that didn't affect the portrayal of the character, everyone else was good nothing special to add.
Character development was excellent especially shenzi the hyena in my opinion.
Subtle details that are extremely subtle can be missed by some but just keep an eye out, one I will point out is that scar gets slightly larger once he becomes king, after all his feasting.
All in all I'd give a 8.5/10 which is disappointing when this should have broken the scale, but the film its self isn't disappointing I think it just lacked some emotion when it needed it, leaving you feeling slightly underwhelmed, plot is excellent and you are definitely eager to see what happens.