Is SE IV worth buying. In a word, yes. Did you enjoy the demo? If so, then you will enjoy the full Version.
The game has a lot of hours of game play. I spent the money, and am happy that I did. Very happy. In fact, I have not gone to work in over 3 months because of this game. J/K
The game is a lot of fun for me, and I have shown it to others, and a few of them have ordered it.
All I can offer is this. If you enjoyed the demo, then get the full Version.
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"We've made too many compromises already, too many retreats! They invade our space and we fall back -- they assimilate entire worlds and we fall back! Not again! The line must be drawn here -- this far, no further! And I will make them pay for what they've done!" -- Patric Stewart as Captain Picard
UCP/TCO Ship Yards