Help me flesh out this idea: Bullet Arena (PvP shmup)

[Vexorg]

With the release of Microsoft XNA Game Studio, I think I have finally found a game design platform which I will eventually be able to work effectively in. Although I have had ideas in my head for various shmups for a while now, this idea popped into my head tonight while I was looking at a Pong code example for XNA, as well as some Senko no Ronde videos on YouTube, and seems like something I might even be able to build eventually. I will try to add more descriptions as I have time, as well as some illustrations to give a better idea of the gameplay mechanic I'm trying for. As the title indicates, feedback would be appreciated.

-V

Bullet Arena (temporary title until I can think of a better one)
Gameplay concept v1
9/4/2006

Description:
2D player versus player horizontal "Shooter" (term used loosely, since there will be little actual shooting by the players taking place) where two players compete to see who can survive the longest among an increasing mass of bullets generated both by attacks from a common enemy (a drone which fires bullet patterns from the center of the arena) as well as each other. In order to perform attacks, players must obtain power through bullet grazing and obtaining powerups which will bounce around the arena. As the players gain weapon power, they can use it for offensive attacks. The player who is best at dodging the various attacks will win the game.

Influences: Pong, Air Hockey, various shmups (primarily Cave style manics), Senko no Ronde
Minor influences: Psyvariar, Twinkle Star Sprites, Mars Matrix (and other Takumi games), RayHound (Doujin game), Dimahoo

Setup/Environment:

Since this game will be written using the Microsoft XNA Framework, it will be targeted at the Windows and the Xbox360 platform. The game will also be designed to emply the Xbox360 controller as its control device. Since these platforms are capable of handling HD resolutions, the game will be designed with a 16:9 screen resolution in mind (on a 4:3 screen, the playfield will probably be letterboxed.) The two players will be located in opposite halves of a horizontally aligned screen. The players are unable to cross into the opposite player's territory, but they will have full 2-d movement through their own territory. They will be able to aim in any direction in a roughly 135° arc facing the opposing territory. Between the two players, a "drone" will roam along the center line of the arena firing bullet patterns simultaneously at both players. Although the bullet patterns fired by the drone should be relatively equal, It will be possible to attack this drone and temporarily disable it from firing at your side, although doing so may raise its aggression toward the attacker.

Objective:

The ultimate goal of the game is to outlast the opposing player by being more able to dodge the various attacks. The game should be designed in a way to place the emphasis more on bullet dodging than on attacking.

Gameplay sample:

At the beginning of the game, Player 1 and Player 2 each choose a fighter (the fighters are differentiated primarily by differing offensive bullet patterns that can be generated. Each ship will have 4-5 attack patterns at its disposal, selectable by using the right and left shoulder buttons on the controller (alternately, the players can have fighters with generic abilities, and be able to select their preferred attacks from a list of choices. After the fighters have been selected, the game will begin. Each fighter will have a small amount of attack energy at their disposal at the start, and would only be able to perform very basic attacks which would probably be easily dodged. At this stage, the primary threat to each player will be the drone, which will initially fire relatively basic bullet patterns at the players. To gain atack energy, the players will need to "graze" the bullets being fired at them, although by doing this they put themselves at risk of being hit by these bullets. There will also be power-up items which will appear on occasion, and bounce around the arena until collected. These will provide moderate amounts of energy, but the main source of attack power should be grazing.

Each player will have a basic weapon (a straight shot, although some fighters may also use a spread weapon) at their disposal at all times, although the firing speed and projectile speed will be relatively low, thus making its effectiveness as an attack weapon relatively limited. This weapon will also use attack energy when fired. If a player runs out of attack energy, they will not be able to use any of their weapons until they have regained enough energy to do so. As players gain energy, they will be able to apply it to larger attacks. These attacks will be activated first by selecting the desired attack from the player's arsenal, then charging it (note that although a player will be able to aim when charging, they will not be able to move, and thus may put themselves at risk), finally releasing the attack when it has charged. The intensity of the resulting attack will be based on the amount of available attack energy and the amount of time that the player charges the attack for.

Attack energy will also be usable in a defensive capacity, although I have not yet determined how this would work (ideas on this would be appreciated.) As I write this, I envision a system where the player's reserve of attack energy will somewhat mitigate the damage resulting from successful hits, and being hit when the attack energy is depleted will have more impact than when the energy reserve is relatively high. If a player is unable to dodge attacks, they will lose health when they get hit by bullets. Drone bullets will do roughly half the damage of player bullets, thus making it less likely that a player will be knocked out by the drone. The game will end when one player's health has been depleted (or a time limit is reached, although I will likely make the time limit optional if it is implemented.)


Controls (based on the Xbox360 controller):

Movement: Left thumbstick or D-pad
Aim: Right thumbstick (as mentioned previously, aiming will be limited to roughly a 135° arc facing the enemy screen)
Select attack: RB/LB(Right and left shoulder buttons)
Basic attack: Right trigger
Pattern attack: Left Trigger

[Shatterhand]

I liked the whole concept.

For a defensive feature, you could make that when both shoulder buttons are pressed at the same time, you turn on a shield that reflect your bullets, but it drains your attack energy (Maybe it would just draw the whole attack energy, and the time the shield stays on would depend on hoy much attack energy the player has at that moment).

This way the defensive feature also becomes an offensive feature. Maybe when reflected, a bullet could become two bullets, so if you manage to reflect a whole pattern of bullets, the returning pattern would be more agressive. AND if the other player then reflects the bullets AGAIN, it would be even more aggressive.

Dunno if this could hurt the main idea of the game though.

[Vexorg]

I did give some thought to using a Mars Matrix style reflect barrier, but I did have some concern that it would take away somewhat from the emphasis on bullet dodging. I'm thinking that instead of that, I might put in a system where a player can quickly launch a counter-attack (without the normal charge time) after successfully dodging an opponent's bullet pattern. Either that, or I could have the reflect barrier as one of the player's selectable attacks. If something like that is being put in, the trick is to figure out how to balance it. Again, I'll try to put together some basic illustrations of what I'm thinking of here, and eventually I'll try to put something together in XNA as well.

[BulletMagnet]

Interesting idea. One other doohickey I might toss into the ring is a "slow down" button which allows you to either zoom out of trouble faster (when not holding it) or dodge more precisely when you use it. To add an extra layer onto it, you might borrow a mechanic from the Shanghai Alice games (most notably Perfect Cherry Blossom) by giving players greater rewards for scratching bullets when not slowed down, adding a risk/reward factor. If you wanted, you could even include an option to turn the slow down button off, I'd imagine.

All the best on the project!

[CodeMonkey]

This sounds like a really cool concept. It sounds like the somewhat natural autobalance nature of the combat will lead to some interesting battles. As one player gets more powered up they will be firing more bullets, providing the other player(if they are good) more opportunity to recharge their guns to counter-attack. I love this core concept already.

I also already like your concept of health loss rate being tied to energy level as a sort of natural shield mechanism.