Disclaimer: This article contains custom card designs. If you are a Wizards of the Coast employee you have my full permission to use any designs or ideas within this article without my explicit written consent or prior knowledge, or without giving me any sort of credit. I love this game and I want to help it in any way I can.
Unearth is basically Flashback for creatures as we know, but it offers considerably more versatility because of how many more things you can do with creatures.
Attack, block, sacrifice, equip, trigger, et cetera.
Unearth was pretty groovy the first time around, but I'm convinced that there's a lot more design space for it, especially were it to be bled into a new color.
As far as limited was concerned, Unearth gave you access to varying sizes of Ball Lightning variants; one free beefy swing. Kind of dull design space, but a necessary utility since limited is very much a big deal.
Plus if nothing else, we get an Unearth hydra. Hydras are cool.
Another way to make use of Unearth is to consider that all Unearth creatures have haste by default. To me this would indicate that Unearth creatures with tap abilties would be a neat trick, but we didn't see much of that the first time around, which I consider to be a shame because of all the neat things you can do with that sort of functionality.
We didn't see many tappers the first time around because a lot of the higher level unearthers were built around enter the battlefield or leave the battlefield triggers, and I really can't blame them. The design space is so obvious, and with Magic mechanics, you generally want to go for the obvious designs first, because otherwise you'll have insufferable know-it-alls like me asking the designers "Why didn't you do this totally obvious thing?!"
One thing I am surprised never happened was that we never got any cards that gave you a bonus for unearthing them, which is to say that when you Unearthed them you got something you didn't the first time around.
And finally, we didn't see much of things that were built around Unearth. Oh sure, there were a tad more than usual discard outlets at lower rarities, but nothing that called out Unearth explicitly. I'm surprised we didn't see the token "uncommon red enchantment that deals damage when you do a thing" or just *something* that would incentivize players to build unearth theme decks.
Whatever happens, I know that Unearth has enough resonance and design space that they'll definitely bring it back in the future, and I can't wait to see how my predictions pan out then!
What do you think about the possibilities of Unearth or how it would have fared for the Golgari?
Let me know and feel free to join my contest!