Just 3 random thoughts on it:

1) is there a particular reason why you need funding for the prototype? I know creating a good prototype that you can actually show to an external bunch of people, let alone your future customers on kickstarter, will cost a lot of time to create at least, some serious money too if you lack the skills and manpower to do all yourself.

But expanding on what Tom said above, your Kickstarter will come over as asking for venture capital that either you yourself or some angel investors are expected by pretty much everyone to provide.

Its the part of the risk in game development you most probably will not be able to delegate, surely not to your customers.

If creating multiple prototypes is the problem, just drop the idea and go with a single one... see random thought #2 and #3

2) While it seems people really enjoy being able to get some say in the development of a game, and multiple indie devs had positive reactions on actively involving their Kickstarter crowd in their development, there need to be constraints set into place.

As the saying goes, people know what they want, put they don't know what they really need.

They might choose a prototype that will do poorly later on just because you attracted a special breed of gamers with your campaign that are attracted to a total niche of games. They might not really be able to judge your prototypes correctly, because a really great one might miss the fun yet while a shitty one might be hilarious just in this small, unfinished state.

3) Your campaign will look chaotic, lack focus and might confuse people, if you present your multiple prototypes. It might be better to get a closed group of "focus testers" to try your prototypes, narrow down the selection based on their feedback, rework the chosen prototype to include features generally liked in the other prototypes and omit the bad features from the prototype, and then create a focused Kickstarter for that one prototype, giving your Kickstarter crowd clear, well defined ways to participate in directing your development in small ways, without literally resorting to the "room full of monkeys on keyboards" for setting your highlevel objectives.

Maybe let them vote on the inclusion of some features selected from your prototypes. Do they think you need housing? Should you include forging items? But the main theme, lock and feel and overall gameplay of your prototype should already be decided, so you can make a focused, consistent impression with your campaign.

The good thing now is: your first bunch of prototypes do not need all the polish in the world, as your "focus group" will include people that know they are testing an unfinished prototype, that might or might not be your future customers, that you will be able to communicate with better to make it clear they are not seeing the final product. You can concentrate on the gameplay first, before needing to add all the shiney graphics people on Kickstarter might judge your game by. You can do that now for one single prototype, while the others will be scrapped before costing you much time and bling.

They say that swarm intelligence can beat any other kind of intelligence... at the same time, the saying "a million monkeys at typewriters could reproduce the works of beethoven" also has its negative side: Will a thousand monkeys be enough for at least a second rate one hit wonder ?

People pay when someone present a vision larger than what they could imagine.

While 'customers' (like you and I) don't necessarily know what we want, and generally know what we don't want, it is the sheer feeling to be presented something we had not imagined but that caters to a need deep inside which compels us to spend on Kickstarter.

Your approach is entirely different: you want strangers to trust you that you're the best person to come up with interesting prototypes with their money, without proof. It could be true, but without proof that you DO have great ideas in the first place, that is unsustainable.

well, just so happened somebody who did just this stumbled into the chat today

Prototype kickstarter:

https://www.kickstarter.com/projects/1644169243/oozengard-r-re-rebooted

actual game kickstarter

https://www.kickstarter.com/projects/1644169243/oozengard-tower-of-power

Slightly different: the first Kickstarter was looking for funding to create a higher quality prototype to a single, already existing game idea.

The TO, as far as I understood, is looking for funding to create multiple prototypes for people to vote on. So yes, could be he meant going into the first rounds with 6 game ideas, to produce prototypes of a high enough quality for people to really form an opinion on.

Still, you now need 6 times as much content on your campaign page, as you cannot make the description just a 1/6 of what it should be, and my point about the whole campaign lacking focus still holds true.