The game length option in fact gives you the following choices, in years:
  20, 40, 60, 80, 100

As described in the manual, you can turn the ENN video segments off if you
find them distracting. If they are off you will still get necessary
information - but via quicker, still-pictures. You can switch ENN off, on, or 
set it to "MIX". This setting will play full ENN video for occasional news
stories only, and will usually give you a static picture.

The "End Turn Save" option increases the time taken up by the computer
between turns. If you want the fastest processing between turns, make sure 
this option is off.

For the toughest challenge, set difficulty to "Hardest" from the 'Set The 
Challenge' box, and/or give yourself less starting cash. Difficulty level
affects the cleverness of the AI players, and sets whether you first, second,
third or fourth each turn.

There is a display toward the bottom right of the main screen (just under the
spinning E-mail 'e'). It serves as a rough guide to how well the four
Powerhouses are doing, in three different areas. These areas are: current
cash, energy supplied and environmental damage caused. Switch between these 3
areas by clicking on the icon to the left of the horizontal bar chart. The 
bar chart now displays performance levels of all Powerhouses in the area
chosen. The number to the right of the chart is your standing in the chosen
area.

The manual states that, when you build a transformer, the computer will
decide which other transformer to connect the new one to. In fact, you can
manually specify where energy from each transformer should go. Right-click on
a transformer and use the new Connect button to do this. When you build a
transformer, you MUST use Connect to specify where energy should go. If you
don't, your transformer will do nothing.

There is also a new overlay - the Power Network - which you can use to check
out how your transformers are connected.