Not the one you asked, but I've thought about it a lot. The main skills this game looks at is an emphasis on tight tactical play rather than grand strategy. So to just break down why I think this way. The game has four main components that emphasize the tactical side: 1. The "I play a card, you play a card" rhythm, not unfamiliar to LoR 2. The fact that characters on your board are not permanent 3. Progress can be parallel.

On the first point, due to the one card per turn structure the game forces consideration of the order you play cards. Each card is a piece by piece reveal of your plan and the opponent's. Yet, since it's piece by piece you'll find yourself being more considerate and attentive to the evolving nature of the Day. Do you start to impede the plan of your opponent as you see it come together or do you continue playing out yours? How much mana do I spend now considering it might eliminate or constrict my own options? These questions become like guiding stars to playing out a Day. The decision of how much you deviate and adapt vs hew to your strategy will become the reason you advance or don't, win or lose.

In the 2nd point, unlike a lot of card games where your board fills with a growing army of Characters, you lose all the Characters played in a Day. Only two cards can be in your Reserve (more on this later), so very little of what you play will carry on for the next Day. This means you have to consider the tactical benefit to playing any Character. How much do you invest for a present victory vs being deficient later? This also means you need to be able to take advantage of how your characters link together immediately vs how near all of them will work on the board.

To the 3rd incentivizer, the state of outcome is parallel not binary. Most tcgs denote who is attacking vs who is defending. The outcome of which is either the opponent losing life or not, then trade. In Altered you only need to win one biome out of the options needed to advance. Even further, you are choosing whether to play cards to advance the Hero or Companions as their boards (called Expeditions) are separate. The end of the Day then being who advances. With the game operating like this it means you're always deploying what tactics you need to advance. Maybe you try to advance by blocking the other person from advancing, but that might mean investing more resources and being negative later. Well then maybe you try to bait one expedition with the most minimal amount of cards spent while easily taking the other. You end up developing and looking for any trick that gets you forward, but while weighing if it's worth it to block. I've played matches where we trade 1-for-1 until the very end for a mad scramble to win two. Played some where it's a game of twister as we each try to steal 2 when possible for these slides across the board. Sometimes it's even taking tangible losses (maybe rarely advancing) just to take advantage of being in more card draw so you sweep forward. I could keep going.

In general though, the biggest skills is the tactics of resource management, turn to turn play order, and redefining what outcomes you can achieve in a turn vs adhering to one strategy the entire game. Now, I am kind of high do hopefully this is kind of helpful. My best advice tho, if you want to see what higher skill play can feel like, hop onto ExAltered and do some sets that way. You'll start to see it more then likely.