I Was looking more for something like this, I understand that you have named the game types but never defined them for "newer" gamer's some gamer's have never played a single AFPS before, and this could be their first introduction to the Genre
The available game types are
Assault — It is an objective-oriented game type in which one team attacks the objectives (usually one at a time in a specific order) while another defends. Often, attackers will be rewarded for completing an objective by being allowed to spawn closer to the next objective. If the attacking team completes the final objective within the allowed time, the teams switch roles and another round on the same map begins. If not, the original attackers lose. If a second round begins and the new attackers complete the final objective in less time than the first attackers, they win; if not, they lose.
Onslaught — or ONS is a vehicle-based game mode in which the objective is to capture a series of power nodes connecting your and your opponents’ bases and destroy the power core located within their base. First team to destroy opponents’ power core wins.
Bombing Run — Each level has a ball that starts in the middle of the playing field. Your team scores by getting the ball through the enemy team's hoop. You score 7 points for jumping through the hoop while holding the ball and 3 points for tossing the ball through the hoop. The ball can be passed to teammates and is dropped if the player carrying it is killed.
Capture the Flag — Your team must score flag captures by taking the enemy flag from the enemy base and returning it to their own flag. If the flag carrier is killed, the flag drops to the ground for anyone to pick up. If your team's flag is taken, it must be returned (by touching it after it is dropped) before your team can score a flag capture.
Deathmatch — or DM, is a game type, in which the point is to either reach a certain number of frags (or kills) or to the highest number of frags at the time limit for the match.
Team Deathmatch — Two teams duke it out in a quest for battlefield supremacy. The team with the most frags wins.
Invasion — It is a simple survival mode. The players are forced to work together to try and survive endless waves of monsters from Unreal that get increasingly difficult with each wave. Once a player dies they cannot re-spawn until the round is over. Rounds can either end after a time limit (victory) or when all players are dead (failure).
Double Domination — Your team scores by capturing and holding both Control Points for ten seconds. Control Points are captured by touching them. After scoring, the Control Points are reset to neutral.
Last Man Standing — Each player starts with a limited number of lives. The last remaining player to still have lives wins the match.
Mutant — All players start in a deathmatch setting with all weapons, and the first player to kill becomes the "mutant". This player receives unlimited ammo, camouflage, Berserk (Increases rate of fire and knockback) and super speed for an indefinite amount of time, but he slowly loses health and can't pick up any health items. When the mutant is killed, the mutant powers are passed to the killer.
Something like this, you could have added to the "MAPS" section where it shows the game types available for the said map.
those could be links that pop up giving the defined "rule set" or intended play style of the match. I dunno I guess I just was looking for a bit more depth. Each game type/mode could also have its own "Trailer" 2-3 minute video showing off the features of the game type and showing game play with a voice commentator telling people the rules / explaining the game mode in the tutorial - I have not actually done a tutorial in the game yet so I don't know if this already exists in game.