i would say a bit different each time:
Reloaded was pretty much remake/sequel of armageddon but with max worms limited to 4 (remake of console-only Worms 2: Armageddon)
Revolution adds fluid/fire physics and objects,2,5d art and 4 classess of worms
[UWSL]Clan Wars[/UWSL][UWSL]
was more of a standalone expansion improving and expanding stuff Revolution did with improved online and workshop support[/UWSL]
W.M.D adds vehicles , buildings and turrets, ditches fluid physics and calsses , and returns to 2d art
none of them really hitting the greats of WWP/W:A but each fun in its own right with its own quirks