If you like shiny, brightcolored two button games that scream FANTASTIC at you every five minutes, so you don't lose interest, RLs might be a wrong gamechoice. They offer depth, immersion, complex mechanics that are 'easy' to get hang of, but extremely difficult to master (in most, coffee break roguelikes usually are more forgiving). None of the attributes I just listed have a prerequisite of fancy graphics. For graphical RLs try LamdaRogue, IVAN, on desktop DCSS (tiles version runs slow as hell on N900), RogueSurvivor, Prospector,,,
Just one argument about graphics: imagine 16x16 icon of an alien hunter in AliensRL that would be as scary as that white capital 'A' when it appears in low light level few steps from you. Not sure if any artist could create a pic that accomplishes such effect. Maybe that's why aliens almost never are shown in the original movie...