I have to recommend against mario and luigi partners in time
first let me say this.
the GBA mario and luigi super star saga is about a million times better.
partners in time has repetitive areas (basically every area is a dungeon) stupid puzzles, a boring story that I just didnt care for. and its sprite work is some of the worst Ive ever seen from nintendo, especially by todays standards.
partners in time lacks a real overworld, instead you just choose which dungeon to go to through the castle, there is no replay value except for playing through the game again.
if you havent played superstar saga before, I recommend that as the DS's best RPG
I still play it on my DSlite, just wander around its world, go surfing, play the arcade games in the mushroom town.
partners in time is the one game in my collection I truely regret buying, very overrated