I was a big fan of "Dark Forces" and "Jedi Knight" back in the day, both managed to take the franchise to interesting places whilst remaining great games in their own right. The games that followed, "Jedi Outcast" and "Jedi Academy", whilst fun, both suffered various game design flaws and probably would've gone unnoticed if not for the "Star Wars" license. "Battlefront" provided a limited amount of entertainment, and ultimately proved a shallow experience.
"Republic Commando" actually tries to be creative with the license. It takes the player down routes completely alien to anything we've seen in "Star Wars" games before. Some hardcore fans and purists will probably hate this, but I applaud LucasArts for finally opting to try something completely unexpected, and carrying it through succesfully.
The gameplay, whilst a little repetitive, is kept dynamic throughout, there's never a dull moment to be had. The simple squad command, which allows limited creative input from the player, works a treat in permitting squad command without detracting at all from the action. The level design is solid, and a superb sense of atmosphere is retained in the enviornments.
My only real gripes with the game are the short length of the single player campaign, and the dull multiplayer. Other than that, this is one of the more entertaining shooters of late, and not just for "Star Wars" fans.