Hi

Im designing a coop 2d topdown game where the players need to clear waves of enemies in different maps by using weapons and traps (similar to orcs must die). I want normal weapons with limited ammo as a base (pistol, shotgun, smg, rifle) with turrets, decoys, mines and rolling boulders as traps. And some more ridicolous stuff as powerups (lasers, miniguns, bag ass bombs etc). Map awereness with picking up powerups/ammo will be important.

1. What about enemy theme? The enemies should be stupid AI-wise and easy to make graphically. They will enter at several points and travel towards an "exit", attacking the player if he/she gets to close. I want some variations, like some armoured guys, some quick etc.

Aliens? Zombies/mutants? What are they trying to reach that you must hinder? A portal? How does this work?

2. What would you think such a game needs to be fun? It's coop, two players at the same keyboard, no networking.

3. What coop-based stuff can you have in such a game? (beside reviving your pal:)

4. How would you earn resources/cash? By killing enemies? By combos? By collecting coins in the map?

Thanks for your input and opinions.

Erik

1. What about enemy theme?

Zombies always go down well, they're basically humans but without the moral implications when the player kills them

Then you can add werewolves, vampires and all kinds of creatures walking around(giving some of them more personality, maybe even making it a mistake to kill all of them)

2. What would you think such a game needs to be fun? It's coop, two players at the same keyboard, no networking.

Can you make it one player using the keyboard and one using the mouse ?
The players would be obstructing each other less and it might work nicely with some specialism.

Both control-modes would have to be fun though.

3. What coop-based stuff can you have in such a game? (beside reviving your pal:)

Definately needing some specialism, for example with different characters.

(another option is to let each player just pick X skills for his/her avatar)

Maybe one can fly, having more sight and getting to places the other can't.

Maybe one can build bigger laser-turrets.

One would definately need to have bigger offensive or defensive stats to protect the other while the other is doing (non-fighting)stuff.

Even carrying-capacity can be a specialism, making sure one needs to get to the other every now and then to drop off loot/tools.

etc. etc, when you 've got the game covered in regard to what weapons/mechanics etc you wish to implement, it's ll become easier to decide on specialism.

4. How would you earn resources/cash? By killing enemies? By combos? By collecting coins in the map?

All of the above ?

Having certain important/advantageous items at well guarded places on the map will give some much needed variation.

What if my friend gets sick and i still want to play this game ?
Have you thought about an AI as coöp-player ?

(one that can understand a few rudimentary commands would be preferable,

although you could increase it's avatars stats a bit and have him go all rambo on enemies,

while the player has to try to keep the AI(and himself) alive)

thanks!
Any other input guys?

1) Aliens gives a lot of flexibility, both mechanically and artistically, and I always liked the idea of scrap metal coming to life. Something like transformers meets Short Circuit, where you get a meteor shower, and you can harvest the meteors for resources if you catch them before they transform into killer robots.

2) I think it relies on action and cooperation to be fun, so make it almost bullet hell. In "survival mode", more kills = more fun. See also 3.

3) - Well-balanced player character choices. I would probably aim for some kind of rock-paper-scissors approach, where between two players you can only cover two of three elements, to keep things challenging, and encourage cooperation.

- AOE buffs ("auras") and other effects, like shield bubbles etc., probably triggered by filling an energy bar or similar to encourage players to keep an eye on each other's stats.

- Power-up abilities (like a typical engineer class dropping health packs)

- Linked abilities, where players combine their powers for super-powers, or the distance between them (for example) determines effectiveness.

4) See 1, but do you really need resources? You would easily get away with "Energy" which replenishes slowly, boosted by kills.

- An ability or action which generates resources, but leaves one player defenceless while doing it, so the other has to defend him.

- Capture and defend resource points.

I think that some of these impacts quite heavily on play style, so choose carefully.