From the website;
Commit the Garde! is intended to simulate battles of the Napoleonic wars on the grandest of scales. Entire epic battles are represented; no longer must the players extrapolate the results of the entire battle of Waterloo based upon their game's recreation of the fight for the garden gate at Hougoumont. Players represent the highest level leaders in any given battle, and as such make the decisions that will shape the entire battle. Gone are the minutiae which their historical counterparts left to their subordinates, your focus is on your army's brigades, not on the battalions and squadrons.
Decisions made by lower level officers are abstracted into the mechanics of the game, players should understand that there is someone at the lower level who should be taking care of those details (spacing of battalions and squadrons, deployment of skirmishers, sighting of artillery sections, availability of spare ammunition, etc). Like it or not the real commanders had to trust subordinates to do their duty well. Often these abstract subordinates will make mistakes (represented by bad dice rolls), whether or not your subordinate's failure is catastrophic to your plan will depend on the allowances you have made for that possibility. This of course is a good reason to have plenty of reserves available.
And speaking of reserves, the most unique aspect of Commit the Garde! is the use of off-table reserves. No longer can your opponent see the deployment of your entire army. The location of your reserves is not determined until you commit them to the battle, at which time you place them where you want them (with limitations based upon distance from your Army HQ and proximity of enemy forces). The skill of your army commander and staff determine how effectively you can commit your reserves.
The game is played on a hex-grid map; the reason for this is to remove the ambiguities of "free movement" common to most miniature rules. With hexes there is no doubt about a unit's location, it's facing, and what the range is to any other unit on the battlefield. The intent with this approach is to make this a game/simulation of decisions, not of inches.
Page count 41 (2 books)
2 Introductory Scenarios (Valmy 1792 and Corunna 1809, 8 total pages and 2 maps)
Playing time (2-6 hours, depending on scenario and number of players, more players = faster play)
There's a SAMPLE file there also!