Like the game before LoB that was similar, Legacy of the Ancients (LotA), it's a quite huge game to play through, and is considerably larger than LotA. It took this reviewer weeks the first time even with preparation with full maps of the continents, towns, castles, and dungeons downloaded from fan sites, and having taken a relatively moderate approach to exploration aside from the main objective. As for full exploration from scratch, if it took me three months on one character to fully explore and map out LotA without any outside help the first time I was able to win it, LoB conversely should take most people that just dive into it quite some time indeed to fully explore.
LoB is similar to
LotA in that it uses the same engine, and this will become readily apparent to anyone that has played LotA before. As such, it brought forward and enhanced the same selling points of innovation that LotA originally sported like the 3D dungeon graphics system and unique cities. The improvements are a lot in some areas, while only slightly in others. The graphics are slightly different in the areas that LoB resembles LotA graphically, appearing to be more detailed in many areas, is and more variant such as with the terrains changing appearance between the main continents. The mini games within the main game, similar to what LotA had, are also more numerous in LoB, as are the subquests (though I didn't complete all the subquests myself when I perused a walkthru). The plot is thicker in LoB and there are more NPCs you'll need to deal with. The character advancement and inventory management systems that LotA originally had are also more diverse in LoB. You're able to do more things in the cities in general, such as working for a day for cash, or utilizing the now more varied gambling casinos. There are more creatures to battle and interact with, more towns and castles, more land on the overland map, and many more dungeon levels with a greater variety of dungeon creatures and challenges. Even the multi-terrain system that LotA had originally has been expanded slightly. The designers also included one last little challenge before you beat the game, which while I won't spoil, this reviewer considers it a memorable final addition to the original engine.
The general menu-system interface for anyone that isn't familiar with LotA should be easy enough to figure out, and you can operate your character via the keyboard or mouse, though a combination of the two is oft recommended. There's also an in-game demo. For those familiar with LotA, LoB is harder than LotA, in some places considerably so. Overall it's a game of medium to hard difficulty as like-RPGs such as the early Ultimas go. Building up your character seems to be more difficult than in LotA, depending on how far you want to go with particular stats. I thought the shotput-like mini game was fun but was insanity to try and fully experience without game-slowing via an emulator. The castle levels are also considerably harder, the guards getting tougher as you progress and the puzzles quite difficult to work out (I thought), almost assuredly requiring note taking in some cases (cough, cough, citadel teleport system, cough). The dungeons are also more difficult and deeper overall than in LotA; in one dungeon, there are as many levels in just that dungeon than there were in all of LotA's dungeons combined.
While the main quest won't change the second time around, the game nonlinearly lets you go through subquests as they become apparent, and at any point on the overland map you may also veer off and attempt to improve your equipment and skills before proceeding. The castles are fairly static in their difficulty, so as a general rule, the tougher you are the better your chances each time through. As for dungeon exploration, I noticed with careful route planning and maps I noticed it was possible to go through the majority of the dungeon levels without needing to use one healing item from my inventory, but suit yourself if you wish to prepare more thoroughly for a brute-force offensive. The game also lets you take your time as you wish for character building, steadily releasing, for example, better fighting equipment up to a point, over time, just as it LotA did.
Like in LotA, there is one bug that I know of that carried over to LoB: Dungeons will repopulate with treasure (if it's not unique treasure) and static healing objects if the game is reloaded in the middle of exploring a dungeon. While that's not a critical bug that will crash the game, this reviewer considers it cheating to use after getting to the bottom of a dungeon, for instance. I didn't encounter any other bugs in the game, though there are some oddities with the gambling system, I noticed, such as they don't tell you at what point you'd be breaking the bank and tick off the guards, and yet each type of game seems to have a different amount that this happens at. Gambling, though, is optional, and seems to serve as side-entertainment, as some gambling endeavours in LoB are statistically unprofitable, just like real gambling. :p
LoB comes recommended for anyone that remembers LotA, or just likes a nostalgically good, very long play with RPG.