Overall this one's a dud for me, especially with giving dice pools to full caster classes, seriously Wizards, what are you smoking. Even worse is that the number of dice given is roughly comparable to classes like the Battlemaster. At 20th level you'd need two short rests for the BM to overtake the druids in dice pool number. The whole dice pool mechanic should really be applied to martial classes only as a method of differentiating them from casters (and giving them much needed options) but no, Wizards have elected to just keep giving magic users more and more.
Alternate wildshape rules really do nothing but aggravate players from where I sit, it's a slight nerf to land druids but moon druids are still overpowered because they can still select all the good forms right off the bat. If they're going to nerf it then I'd rather they just just come out and do it rather than pussy-foot around with DM adjudications.
Circle of dreams is pretty great aside from the dice pool. Remove that and I think it's a neat support/utility option.
I'm with one of the posters upthread though regarding spirits, if you're going to have a class that summons them, said spirit better not be an immobile, inactive lump that hands out auras. Go hard or go home on this one in my opinion, make it a summon with unique stats that you can sacrifice spell levels to modify or increase its power with. Basically anything other than this bland, flavorless excuse of a path feature. The others aren't great either, a mediocre summon when you go down and speaking to animals are both pretty blase. Overcoming magic resist with summons is good, but this one needs work.
Necrotic druid would work better if they just went back to it being a blighter, but a lot of this smacks of cleric lite, like death saving throw advantage and speaking with the dead. In addition to being another annoying dice pool, harvest's scythe is ridiculous for alpha potential, and even comes with some healing riders to boot. As other have noted, it's also really weird that an anti-undead option deals necrotic damage.
Overall, I'm really not impressed by Wizards' offerings of late. It seems like they're not making good use of this testing/feedback space because they're just not going outside people's comfort zones enough. Hopefully they'll get a little more ambitious as time goes on but I'm not holding my breath.