When you played Republic Commando the other game came to mind -- Halo. You could definitely notice many similarities, but it didn’t mean that the game was bad, on the contrary -- it was one of the best first-person shooters based on the Star Wars lore.
Although it had no Jedi represented in the game and the single player campaign was one of the shortest in the franchise, generally the audiences really liked the concept of Republic Commando. Despite a massive success, Republic Commando never got its highly-anticipated sequel.
Even after more than 10 years the game still holds up in both the graphics and sound departments. So, if you want to know what happened in between Episodes II and III, then check this game out.