The old pages are on the left, the new on the right. Where there are multiple pages, read left to right.
The snail is canting more dramatically, and is more clearly wounded. Axel's pose is more active, indicating effort and tension, and he's yelling with greater urgency.
The redrawn panel shows much more anticipation: there's contrast between the guys getting ready and them being focussed that makes the panels move.
New: The discipline from the previous page follows through with all the spears going in the same direction; the jubilant hunters are better depicted. Note that while there's less wreckage, it's more carefully depicted to resemble stuff that could come from a toll booth.
New: Axel is sitting (well-earned!) and is given a full page to consider what their new weapons enable and what it means going forward.
Left (old). Right two (new): the monsters get more space. The additional space on their panel lets the closest monster's tongue look like it's coming out *at* us. There's also space to show Suiryu pulling up and looking to help -- all shot from a low and dramatic angle.
New pages: Ryumon is shown actively shooting. Other than the drama, his position respective to the monsters is much clearer.
Redraw only: Crescent Eyebroll tries to right himself, and we see why the monsters are so hard to kill (they regenerate). Suiryu appearing distracted is a nice clue to what's going to happen next.
Redraw only: The charging Neo Heroes find their prey unexpectedly easy to kill. Suiryu is the only one tracking what's happening -- Saitama just happened to be passing through!
Redraw only: we follow through with Saitama and what he was doing. Being technically incompetent and yet doing good as he bumbles along -- classic! Love that we're left wondering what he and the Name Victims' Group are going to be doing next.
Redraw on right. Now we have context as to what the heroes, monster, and A were all doing.
Redraw only: A's attack is given several panels that work with the scattering birds and choice of background to create a sense of menace. Also, admire the fish head anatomy!
What a difference a black panel makes! On the left, it's just a divider. On the right, it's the thing making you wait for what happens next.
Redraw: Not only had we no inkling this was coming, we're right up close, almost within touching distance of Zaedats as the life is crushed out of him.