In hindsight, probably should have included a trailer for Light of Motiram in the OP on second thoughts, my bad:

It's pretty blatant, I'm not surprised Sony are pissed.

Yikes, the resemblance is uncanny,
This is gonna end well.

Its great that developers are inspiring each other, but this just looks too close to Horizon. Looks like a well made game, so Im surprised the developers didnt try to diffirentiate it more.

SNY does what....... Nintendoes......?

Wait, that's not how it goes!

Mediocrity ripping off mediocrity. 

Well I certainly see the similar style on the over all ideas. But man I see stuff from Breath of the Wild, Monster Hunter and others in there as well. Heck looks like you might do some upgrading the beasts you ride on for a little Banjo Kazooie Nuts and Bolts in there as well! :)

Tencent is going to win this easily, the game looks similar, but a lot of games look similar and Nintendo also didn't have a case for Pallworld.

Judging from gameplay videos, it looks quite different from Horizon. It does not look like a ripoff in that regard. Some of robot designs and some other aspects of the presentation are a bit too similar though. Other things are similar, but weren’t uniquely “Horizon” in the first place. Still I think they would have gotten away with it had the marketing material not been so shamelessly trying to make it look like a Horizon game. As others have said: It is as if they were begging for Sony to sue them.
Maybe that was the idea, to get people to talk about the game.

Well the Palworld thing is ongoing, but even there Nintendo didn't use copyright but instead patents, which are more complicated and broad. I agree that I doubt that Sony can win on the base of copyright, for that you must explicitly copy something, looking similar isn't enough. The case also claims trademark infringement which might work better if they can claim some elements of the Horizon series as trademarks.

The point here is that Tencent approached Sony to get the Horizon IP for the game, Sony declined, and they still went ahead with it.

Simply being a ripoff would hardly be reason enough for Sony to sue and win it, but Tencent actually wanted to be making it a Horizon game, and got cheeky after being told a "no".