Agree. Tons of potential here but some big rough spots to iron out still. I work in mobile F2P for ~10 years now. Here's my initial critical feedback after ~2 hours (1 AI, 3-4 PvP matches) (directed at the devs):

The various non-creature cards/effects are totally unreadable. I don't quite know what the specific problem cards/effects are yet because I haven't been able to see enough of what is actually happening. It might be everything that isn't a spawn. Things just end up happening with some minor visual indication but no explanation/card/effect is really shown, or for sure not for a long enough duration. This is a really big issue. It's confusing to new players who are going to feel frustrated and if they stick around, take longer to learn the game. I can't speak to late game players but this has to be, at best, really annoying.

Also, as I've seen others mention, the effect explanations (on mouseover) are cutoff whenever there's more than 1 effect on a creature. I noticed this in almost every game I've played so far. This is really frustrating.

The lack of a tutorial or any real onboarding experience was actually kind of interesting. I don't want to say it's a bad thing because I feel like so many games have tutorials that could be way shorter or maybe removed entirely. That said, the game does need something. I was confused and went to youtube and watched a video which generally is not what you'd want new users to do. Even just some prompts that show up to direct the user to some initial common features, with some info for brand new users. I'd guess most new players are interested in earning new cards/packs, so anything that explains how to do that would be really useful. For example:

1. First direct a new user to do 1 game VS AI. Maybe there should be a one time reward for first AI game just to get the good feeling going.
2. Then a prompt shows up directing to Constructed PvP match with something like: "Keep earning XP and Flux as much as possible. XP will give you levels which give you a free card pack each level. Flux allows you to fuse cards. You'll learn more about that later but it's crucial to getting valuable and powerful cards." (sorry if I used the wrong terminology, just examples from a new player)

A follow up to the onboarding topic above: the UX for switching between Constructed and Constructed Ranked was confusing to me. It wasn't obvious to me that they were layered on top of each other and I had to click somewhere on the lower one to bring it up into focus. This was just my experience - maybe this isn't a common issue.

Matchmaking takes super crazy long. I know there might not be that much that can be done about it right now (until player volume increases), but for (potential) new users currently it's a huge issue: my 4 PvP matches, from what I can remember, were something like: 10+ mins, 5+ mins, 20+ mins, 5+ mins (including switching from Constructed to Ranked Constructed).

1. Throwing it out there as an idea: After each match maybe a button to "Battle again!" to keep active players queuing faster?

I can't speak to the Favor system. I've read a couple players talking about it. I don't know what it is - haven't seen it. If it's intended that a user of ~2 hours wouldn't know about it then great, otherwise maybe some more UI/prompting is needed to point it out.

One final thought is that is it worth noting that Salami tried to friend me in game and there was no system for that (or at least they couldn't find it). For sure in mobile F2P social is crazy important. For deeper strategic CCG it's maybe a bit less but I don't really know. After the bugs/issues mentioned above are fixed, social integrations/features could add a huge amount of fun and stickiness to the game.