Expansion packs tend to get less interesting with each consecutive release after the original game. While successive releases may be more polished, the game's engine gets a little more dated and it's difficult to offer gameplay that isn't repetitive. Expansion packs for role-playing games, in particular, face the difficult task of rekindling interest in the original while offering new environments and adventures that collectively provide only a small fraction of the gameplay offered in the original game. Bloodmoon, the second expansion pack for Elder Scrolls III: Morrowind, largely overcomes those problems by appropriately building upon the strengths of the original game while also providing an ample amount of new territory to explore.
The new island provides a decent amount of new territory to explore.
While the previous Morrowind expansion, Tribunal, was set exclusively in a segregated city that wasn't even on the map of the original game, Bloodmoon adds a new island just to the northwest of Morrowind's recognizable landmass. Morrowind's dark elf populace hasn't yet successfully colonized Bloodmoon's island, which is dominated by fierce Nord tribes and barbarians. The beautiful arctic landscape is covered in snow and ice, coniferous trees, and rock formations that appropriately resemble Celtic ruins. The thunderstorms and dusty gales of Morrowind have been supplanted by delicate snowfalls and fierce blizzards. While your character is happily impervious to the setting's frigid temperatures, the change in climate and the distinct terrain make even random exploration interesting. And unlike the Tribunal expansion, Bloodmoon doesn't restrict you from freely exploring the expansion's new landmass. While Tribunal provided a story-driven series of largely sequential quests, Bloodmoon offers more open-ended gameplay and a larger territory for free-form exploration, which were key aspects of the original game's appeal.
Monsters frequently attack you in groups.
Bloodmoon's island is also apparently the Elder Scrolls' equivalent to the Galapagos Islands, since it's populated entirely by unique and interesting flora and fauna. There are more than a dozen interesting new animals and monsters, including packs of wolves, spriggan tree creatures that need to be killed thrice to stay down, and speedy undead draugr. There are no new flying creatures, and the sole water-dwelling animal is largely passive, so explorers don't have to worry about being constantly interrupted by Morrowind's flying cliff racers or pesky fish. If you don't elect to travel through the now tranquil air or water, however, you'll have to deal with hordes of rapidly respawning arctic denizens, since the island is practically overflowing with hostile inhabitants. The creatures are also much more powerful than those in the original game, and battles are rarely duels with solitary enemies, as creatures now frequently attack in groups. Despite these new threats, battles are still relatively brief, bludgeoning affairs if you have a well-equipped adventurer from previous excursions, although you can always increase the challenge using the difficulty slider that was added in a patch after Morrowind's initial release.
If you chose to maximize the details of its impressive graphics, the original game's engine was capable of forcing even the most formidable computer systems to run at occasionally choppy frame rates. Since Bloodmoon features even more detailed and populated environments, the practical system requirements have also been correspondingly increased. You should expect the game to play at least a few frames per second slower when you're traveling outdoors, especially since it's easy to quickly pick up a whole band of hostile pursuers if you're trying to rapidly travel between destinations. While Bloodmoon's additional graphical richness helps to justify the occasionally choppier gameplay, the resulting reduction in frame rates actually worsens one of the main problems that many players had with the original game. The developer also apparently paid minimal attention to sound effects and music, which are almost entirely recycled, although nonplayer characters do occasionally bark commentary that accurately reflects the results of quests or other plot developments, which is a welcome addition.