Graphically speaking, right off the bat,
Hangsim is gorgeous; beautifully textured backgrounds and mountain-scapes. At max resolutions of 1280x1024 at 32 bit color, I became light-headed due to the surreal brilliancy of the color palette. The skylines set incredible moods of time with colors ranging from sky blue to sunset orange and purple. The character animations are well done and lifelike and the craft designs are true to life.
The graphics of Hangsim are accompanied by catchy tunes, even during the quick install process. The overall sound effects are well done, however they tend to be limited and repetitive. But this is generally the usual situation with all flight sims. Only so many sounds are heard in the wild blue yonder, I assume.