I have to admit I'm surprised by all the additions to Academy that didn't previously exist in Arena. When I heard what the design goal of Academy was, I expected a lot fewer keywords, simpler cards (e.g. less card text; more cards with symbols only), less multi-card combinations and interactions (like what we see on Steelclaw Matriarch and Slavorg), etc. While there certainly are fewer keywords and conditions, there are many I didn't expect to see (e.g. Dissipate, Elusive, Pest, Aegis, Defenses, Legendary, Unique, Epic) and even even some new ones (e.g. Stagger, which is a little like Daze and Stun but different; a new "breeches" equipment slot).
Even the complexity of card text and card abilities is higher than some Arena analogues. Iguana Regrowth, Wolf Fury and Gator Toughness are all more complicated than their Arena counterparts, generally combining the straightforward Regrowth, Bear Strength and Rhino Hide with Bull Endurance. Similarly, Crumble is like a combination of Dissolve and Meditation Amulet. I expected, and wouldn't have minded, reprints of simple "staple" cards like Bear Strength, Rhino Hide, Regrowth, Dissolve, Dispel, Seeking Dispel, Minor Heal, Block, Nullify, and many of the "Novice" spells like Leather Gloves, Leather Boots, several Incantations, etc. Or simply weaker versions, like Whatever +1 instead of Whatever +2 (for Bear Strength, Rhino Hide, Regrowth, etc). But instead we often get new cards with Whatever +1 AND another benefit. That's great... but certainly not simpler.
In addition, and seemingly more complex than similar Arena cards, we have Azurean Genie, who puts the benefits of Hand of Bim-Shallah (but better, at the cost of his action and range-restricted) on a creature ... except he's even more flexible in some ways since he can Stagger an opposing creature if he doesn't have a friendly nearby! Slavorg is the first non-Incantation card (e.g. besides Resurrection/Animate Dead) that cares about your discard pile, plus he has a built-in Defend effect. And for compatibility with both Arena and Academy, many cards have different/additional effects depending on creature level (including defining Major and Minor creatures) or mage level (something that used to be a single-valued constant), which adds a lot to the card text (e.g. lots of spoiled cards with 3+ lines of text).
Overall, while Academy might have more streamlined and quicker game play than Arena, I wouldn't say it's much less complex. It forgoes conjurations, the deployment phase and the planning phase, but the cards require just as much (if not more) reading, and there are lots of combos to build around. I'm excited for this product, both as an expansion to Arena and as its own standalone game (that I might play with people who aren't interested in long Mage Wars matches - e.g. my spouse) but I'm not sure it will appeal to the desired target audience that it was originally designed for - e.g. new players who were intimidated by the complexity of Arena.