It also depends upon the types of rugby.
Rugby Union is probably the one with which you are most familiar, however I would suggest that Rugby League bears more similarities to American Football.
In Rugby League, you have 5 plays to move the ball, on the fifth you either turnover or kick - this guarantees possession to both teams - which is definitely not a given in Rugby Union. It also allows for more set piece plays, but not to the highly formalised ones in American Football
In Rugby Union, there are specialists who tend not to make tackles - such as wing players, and other who carry the ball only in very limited circumstances, and are not expected to gain yardage.
In Rugby League, every player is a ball carrier, and every player makes tackles, every player will be expected to make tackles that stop opposition players dead, one on one. The result of this is that Rugby League players tend to commit themselves to a tackle more fully, the hits are harder - a Rugby Union tackler must ensure they are available for the rolling play and so they tend to have a lot of delaying, rather than stopping tackles.
Rugby Union is noted for rolling play, Rugby League has plays that last until the ball carrier is deemed to be tackled (sometimes a tackle can mean a ball carrier is standing up but is completely unable to move forward or pass the ball) Once the tackle has been made, the game stops and the players line out for the next play.
Superficially the games may appear similar to the novice spectator, but in fact they are vastly different.
The main ball carriers are fast, the aim is to get the high acceleration from one heavy duty player, who tries to lay it off to someone with perhaps higher top speed, but does not pull away as quickly. In RLeague the main scoring period is in the last 15 minutes, when the toll of tackles has ground players down, and many coaches will have a strategy that will target certain individuals on their opposition to do just that.
Do not underestimate how big Rugby League is as a game - here are some open plays
Here are some heavy hits, the impacts are frequently enough to stun the both ball carrier and tackler - you don’t tend to see them as heavy in Rugby Union - that’s not to say Union player can’t hit as hard, but they don’t do it as often.
In both codes of Rugby, kicking is crucial, its not the sort of pussy footing that you get in American Football, always right in the middle of the field, lined up with the posts - what is the point of that then - too easy.