More the same in this expansion pack for the original puzzle-RPG.
Plague Lord let's you play a few side quests in the southern part of the map. You can do it with your chosen character or just start a whole new one with one of the new classes. If you choose to play with your already high level character you'll find that those new quests don't offer much of a challenge. Exceptions to this rule are the boss fights, which are way too few this time around.
Gameplay is precisely the same as before and since this is an expansion pack that's just what it should be. You form three to five rows of similar items in order to gain Mana to perform attacks by using spells or straight attacks by getting three or more skulls.
Surprising problem is that it's not clear in any way to know where that downloaded extra content is. It took me a really long time to find the quest that lead me to fight against Lord Antharg, which is one of the two main quests in Plague Lord.
Of course the main issue here is: should you buy this game? The answer's yes, but only if you really enjoyed the original experience, have already done everything in it and still want some more. This expansion is for hardcore fans of Puzzle Quest.