Well, here's a few good tips for RPG's.
1. Let the player make choices(i.e., escort a slave chain and get paid, or free the slaves and have the slaves help him later)
2. Always have some new features or new style of play. New and innovative is always good.
3. Make the player feel like the world isn't revolving around him, make the world seem alive. Make people moving, and maybe even have him walk in to some battles taht are already going on.
4. An RPG, unlike some other types of scenario, absolutely MUST have an excellent story to be successful. No offense to anyone who has made anything like this, but I will probably never download an rpg from the Blacksmith if they say(your kingdom is at war with another, this bad guy is trying to take over, blah blah blah.) Spitfire's campaign has an excellent story, however, and I might just buy TC just to play it 5. Make a lovable protagonist(and protagonist's friends). Make your main character and his friends someone the user will want to love, revere, respect, and be proud of when he finishes. You know you have made the perfect story and main character when someone says they felt truly sad when a friend sacrificed his life for the protagonist for example.
6. Make the antagonist fearful. Make a rival character that seems as if he could actually hurt the protagonist, and make him or her someone that the user will love to hate, and also will love to see die/banished/whatever.
I would think of more but I'm too lazy. Hope this helps. BTW, Spitfire, maybe we should both work together on your rpg whatyacallit, sicne collectively we have amazing innovative ideas