you uh, should've shown the page right after that talking about 4D space, where it states that it is simple a "time line", since dimensions there are regarded as "distance/lines" with time being the change of position, and it explains that 3D beings can only feel the flow of time while 4D beings can see the whole timeline, and the god saitama fights during that chapter (which is just one of a whole race, and i assume is commanded by the "supreme god", who sounds like the big bad) uses a ability to suspend garou in time with 4D power
so yeah, while the difference between the spatial dimensions is the usual infinite, 4D there is just time, god did mention that theere are others from even higher dimensions, which i'm still reading and stuff, but for now, i think they might not be tier 1
edit: okay next page also talks about the other dimensions, the manga i'm reading is on portuguese so let me try to explain:
they talk about how 3D beings can "bend" 2D space to help a 2D being cross a distance even faster by uniting point A and B, and relate that to wormholes allowing 3D beings to move through 4D space for a instant.
they then explain that this can extend to 5, 6, 7 and beyond dimensional space by adding more spatiotemporal axis, with the possibility of dimensional travel, then mentions earth scientists believing in 11 dimensions, and that, in the darkest place of the universe, there is a being with more dimensions than taht, who can "bend the universe and it's inhabitants"
for now this is it, i'm now on chapter 3.2