I read the Castaway 2 thread, tried the game, but didn’t like it very much. However, I was poking around Kongregate afterward and came across two that I do like.
Rebuild is a turn based strategy game where you start out with four plots of land and a handful of the survivors of a zombie apocalypse. You explore, expand, exploit, and try to exterminate the zombies all around. The first time I played through I thought it would have little replay value but turning up the difficulty a notch makes it much more of an interesting challenge. I’ve only beaten it once on “hard”. Includes at least one Oregon Trail reference.
Hack Slash Crawl is a stripped down roguelike-- or maybe more a diablolike. Plenty of race/class combos, and they definitely can have different gameplay. So far I like human magus, golem cursed, and vampire fighter. I doubt it’ll ever replace Crawl Stone Soup in my roguelike affections but it’s fun. One nice feature is that when you die you get a title, like “devastating”. You can later pick up to two titles during character generation for bonuses.