He and his teenage son, Dirk, reside in the Dreamer household in the neighborhood of Pleasantview. Darren is a widower - his wife, Darleen Dreamer is deceased before the game begins. Because he has no memory of the fire that killed her, it is safe to assume Darren wasn't present when she died.
He's secretly and un-requitedly in love with his neighbor, and best friend, Cassandra Goth, but she is engaged to the town womanizer, Don Lothario, who he considers an enemy. In the game, Darren loves to paint and wants to be a full-time artist.
At one time, he had a job in the Business career track at level 3 as a Field Sales Representative, but he quit around the time of Darleen's death. When first played, he has seven points of creativity skill, and is 15 days away from becoming an elder.
While Darren considers Don an enemy, Don just thinks of him as an "Acquaintance". This is not possible in normal gameplay, but can be arranged by editing the package files, which Maxis would have been able to do. Likewise, while unrequited-love relationships are possible in normal gameplay (but difficult to achieve), the type of relationship that Darren and Cassandra have would require the use of a package editor, or a hack.
If Darren invites Cassandra over when first playing the Dreamer family, there is a high chance that she will flirt with him autonomously. If this happens, then she will fall in love with Darren, which will instantly cause her to be cheating on Don Lothario, with him.