A solid but brief expansion to a fun dungeon crawler.
Heart of Winter plays exactly the same as Icewind Dale as can be expected. The expansion adds several new areas of Icewind Dale for you to explore (only accessible during the expansion however). Heart of Winter also features an option that makes both Icewind Dale and Heart of Winter much more challenging called 'Heart of Fury' where enemies are more powerful and you get more experience for killing them. The problem with HoW is it is just so short; you can finish the expansion within a few hours, but fortunately Black Isle released a free downloadable expansion for HoW called 'Trials of the Luremaster' which extends the length of HoW by a couple hours or so.
The graphics in HoW are improved by the inclusion of 3d hardware support (what little it does) and the ability to increase your resolution. There are several new enemies added in the expansion and they look decent enough.
The audio of HoW is just as good as IWD. The music is once again composed by Jeremy Soule and the voice acting is the same quality as the original game. The sound effects are the same, but that should be of no surprise and the enviromental ambience is also the same level of quality as Icewind Dale.
Icewind Dale: Heart of Winter is a worthy purchase if you own Icewind Dale; it adds some nice new features and the expansion storyline is good as well as the well designed areas featured in the final product. If you liked Icewind Dale then give Heart of Winter a shot; if you didn't like Icewind Dale then Heart of Winter won't change your mind for it is just as linear and combat focused as Icewind Dale; just a lot shorter.