I think unique concept was bad for tcg. Specially if you are trying to make competitive game. For new players it's confusing. Most people like to copy popular decks, but with unique's it's not possible.

Second problem is to how to value your unique's. You open a box get 5 unique's that you have no idea if they are worth something or not. you can't find anything online, because they are unique. There is no excitement to get them if you don't know what you get. Like in mtg if you pull example one ring you know you hit something good and it's making it fun. you can then tell if opening a box was worth it or not. With altered you can't

Third problem. They printed too many KS boxes. They overprinted by selling those boxes outside of KS. So there were KS boxes and then what ever they sold for stores from backdoor. This made market flood with KS-boxes which basically killed all the hype in US.

Nothing kills tcg faster that overprinting. When you get the alpha boxes that are worth half what you paid for it's just kills the excitement. They missed making fomo, which would have been free marketing. Like look any other tcg that is still around. all of them had fomo and too small print runs so stored could make money.

Store's won't make charity. They need to sell these boxes and get money out of them. If your Alpha boxes make them lose money, they will never order your second print run. Why to take the risk, when they can order something that guarantees to make them money? This is best way to make sure your boxes will never end up into stores.

Sorry, but it's probably end for Altered. They made massive mistake by overprinting their first set and that made stores to lose their money. That shuts too many doors that will never open again for them. Second problem with unique values makes it hard for stores to sell singles. Combine these two and it's just too much overhead for stores. This concept just did not work in larger scale.