I've been playing (probably far too much) Monster Hunter World. The game is awesome, and the gameplay feels like a natural upgrade from 4U.
Honestly my biggest issue with the game is the weapon designs and their options. Most weapons are visually underwhelming, with most being the basic "ore" or "bone" weapon with a few monster bits glued onto them, usually around the hilt. (And poor Hunting Horn users seriously got the shaft in the design department.)
Plus, unlike previous games, not every monster has a corresponding weapon. The Dual Blades for example don't have a Pukei Pukei branch. Without some of these branches, hunters options become limited.
I feel like there were two possible reasons: Either they didn't have time/budget for designing/rendering/balancing all the weapons, and unlike the 3-through-Generations, they couldn't asset-flip much of anything beyond animation.
Or: They wanted a more 'realistic' angle to the game, perhaps wanting weapons to slowly become less 'man made' and more 'monster parts' over time as you upgraded them.
Speculation aside: I just hope, going forward, they move back to every monster having a corresponding weapon with unique designs.
As for the ryona aspects... it's not for me.
Losing all your health just has your character faint and flop to the ground, much like previous entries. The action is also fast paced, so any grabs tend to be over before you have a chance to really see what happened.
So for me, who just wants to see the ladies getting eaten on screen, it's a bit underwhelming.
That said, as mentioned above: You can be paralyzed, both by certain monsters, and the paratoads which you can kick yourself. Being paralyzed leaves you twitching on the ground. A similar toad, the sleeptoad, can be kicked to make your character, well, pass out and sleep.
You can also be dazed, which is the standard "swaying around with stars above your head" sort of animation. You'll mostly get dazed by taking repeated large monster attacks, though one particular monster, the Tzitzi-Ya-Ku can produce a blinding flash that will stun you if you're in range.
There are also a couple of monsters that can leave large piles of mud in which your character can get stuck in, struggling to move.
Naturally monster attacks can also just send you flying, and rolling across the ground.