A handy reference to all the games available here that will run on Mac and/or Linux:

Visual Novel/Adventure
Date Warp
Heileen Series
Bionic Heart
Yo-Jin-Bo (Mac only)
Jisei and Kansei
dUpLicity ~Beyond the Lies~
Cafe 0 ~ Drowned Mermaid ~
Vera Blanc series

Life Simulation
Cute Knight Deluxe
Cute Knight Kingdom
Magical Diary
Long Live The Queen
Spirited Heart
Flower Shop (both Summer and Winter versions)
Summer Session
Lucky Rabbit Reflex - Mac / Linux
Fading Hearts
Love & Order
Always Remember Me

Science Girls
Eschalon Series
Loren The Amazon Princess
Planet Stronghold
The Three Musketeers (Mac only)

It's possible that other games may be run through emulation; this is just a list of games with proper ports.

(c) Hanako Games, 2011