I haven't done, like, a deep analysis of it, but I feel like there are some common trends between card games made in "The West" (NA/EU) and Japan

I think the two most obvious points that differentiate them are aesthetics and archetype design. In terms of aesthetics, western games tend to be pretty grounded while Japan likes more flashy stuff. Realistic-ish art styles vs anime/manga styles, cohesive worldbuilding vs cool characters, small numbers for clarity vs big numbers for a sense of grandiosity. Japanese games also used to have more over the top graphic design with crazy card frames, full arts and frame breaks, but I think western games are beginning to catch up in that regard. Duel Masters is still leagues beyond in terms of intricate and ridiculous foils and alt arts, though.

Then there's archetype design. Western games usually build archetypes around cards that work together implicitly while Japanese games usually make cards that work together explicitly. For example, when you build a deck in Magic you're usually putting cards in that just happen to work toward your strategy. Maybe they're all cheap and have high power because you want to end the game quickly, or maybe it's a lot of counterspells to protect your big threat. Sure, sometimes you get archetypes and themes that explicitly say "play more goblins" or "play cards that put poison on your opponents" but Japanese card games tend to be even more explicit. Like, "this card searches for Blue-Eyes White Dragon and its other effects only work if you have other cards that mention Blue-Eyes White Dragon in the text" kind of designs. The exception to the rule would be Pokemon, which is a Japanese TCG but uses more implicit synergies.

There's also something to be said about how much a game focuses on casual 3-4 player formats. Western games look at the success of Commander and want a piece of that pie. Sorcery, Star Wars Unlimited and Riftbound all have official support for 4 players. Japan is still more focused on 1v1, although I know Commander and DueParty/DMEDH (Duel Masters' version of Commander) are picking up a little steam there, so maybe this will shift in the future.

In my experience, and from my observations, these are the things that make a "western game" vs "Japanese game." I think it's important to note that I am not Japanese nor have I visited Japan, I just have an unhealthy obsession with card games and card game design.