Well, people keep telling me to mold my work on games towards crowdfunding, but while I of course know what crowdfunding is, 'molding my work for it' is not within my experience. Does anyone know what one should work on (in a game) if crowdfunding is being considered? Any advice is welcome, I don't know funding, I just code :)

The main thing about crowdfunding is that you need a crowd for it to work. You need the crowd before you start the funding. You will get some reach just by being on Kickstarter (and less so for Indiegogo, GoFundMe, etc) but rarely will it be sufficient.

The other thing is that 'Kickstarter' is a misnomer these days. Rightly or wrongly, established teams use it to raise additional funds for their projects or just as a convenient pre-order system, which means you're competing against them in terms of the quality of your presentation and marketing materials. The days of expecting Kickstarter to literally kickstart a new project into life are over; you need (in almost all cases) to be able to show good progress towards your goal before you even launch your campaign. Many gamers basically expect you to be at the Alpha stage (not feature complete, but playable with many assets in place) before they'll consider backing it.

If the subtext of your question is "I want to make a game, and to find a full team for it, which means paying them, which means crowdfunding", then your process should be a bit like this:

• develop your barebones prototype yourself, make sure that it works, and get a coherent design together
• pay someone to do concept art, ideally someone who's worked on a Kickstarter before
• find (or, more likely, pay) someone to consult on your Kickstarter to ensure you're doing the right things, offering the right rewards, have a feasible project plan and expenses breakdown that you can share, etc
• plan your shiny and polished Kickstarter page as well as a PR campaign of material to drive people to that page
• Crowdfund!
• ...
• Maybe profit.

Oh, and somewhere in there you need to find time and resources to work on the actual game.

Yes, you do need to spend money before you crowdfund to have a decent chance of raising enough money to carry your project to completion. It's a shame, but that's the state of the market.

All that sounds perfectly reasonable! I don't think I am anywhere near that stage, though, and I was worrying more about the presentation, which you mention. I could probably get some pretty art done and will of course not move until I have something playable, but the question is, what pretty art and how playable? Are crowdfunding websites these days full-on professional designs, or can they be more basic and informative? Is a game that shows the main gameplay but has bugs and crashes acceptable, or are we talking "fake alpha", i.e. a game that is only called an alpha to allow changes to be made before release, but actually plays fully already? I have been looking for examples to guide me, but dangit crowdsourcing has evolved since I last helped crowdfund a project :o

EDIT: Also, stretchgoals and rewards are basically Russian to me. No, more bizarre; I can grasp how Russian works, at least! I have no idea how to promise things without promissing them outright, it just seems loopy to me. But it seems to be all the craze!

Well, people keep telling me to mold my work on games towards crowdfunding, but while I of course know what crowdfunding is, 'molding my work for it' is not within my experience. Does anyone know what one should work on (in a game) if crowdfunding is being considered?

Build a time machine and go back to 2013? ;P

Are crowdfunding websites these days full-on professional designs, or can they be more basic and informative? Is a game that shows the main gameplay but has bugs and crashes acceptable

If no one gets to see it crash, is it really buggy? :D
You need to be able to get the concept and vision across to the players. You'd basically want to be able to put together a gameplay trailer, so you need most of the game mechanics done and maybe one level's worth of fully polished graphics. To do this, you'll probably be forced to write as much duct-taped-together bug-ridden horrible code as possible, just to fake it. So as for tailoring your game -- work on the gameplay features that will get people excited when they watch a one minute trailer, and get enough art so that when you show off that one minute of gameplay features, it looks professional.
Personally, I would not back anything that doesn't look professional. A professional is someone who makes money from their work. If you don't look like you belong in that league, why would I gamble my money on a risky pre-order deal? It's got to excite me and give me confidence that it will actually come into existence one day.
As for press, the press are over crowdfunding. They don't care. I've heard people actually call crowdfunding "cancer" to your press coverage - using the word "kickstarter" will immediately make them tune out and ignore you... So in the lead up to your crowdfunding campaign, you need to send out press-releases in a way that will get people to write about your game without telling them that you're about to do a kickstarter. They want a story, an angle, and they don't get paid enough to do research into no-name indies to find those stories... so you basically have to write it for them. Read the work of as many journalists as possible and take notes as to the kinds of stories that they like. Bend the story of your own project to fit their mold, write a press release in a way that tells the story they want to hear, complete with quotes that they would use verbatim, and send it to those authors personally. This is a hell of a lot of work, but it establishes credibility ahead of your kickstarter...
The indies I know who have crowdfunding and succeeded have: consulted with a publisher/agency to help plan everything (games-specific marketing/PC consulting firms are a thing), hired someone to make their trailer / or spent about a month on it themselves (for a 60 second trailer, that's about 2-3 hours of work per second of final trailer footage :o ), spent about a month planning their campaign, spent the entire kickstarter month working full time on supporting the campaign... and spent long enough on development beforehand to have a vertical slice of their game.

EDIT: Also, stretchgoals and rewards are basically Russian to me. No, more bizarre; I can grasp how Russian works, at least! I have no idea how to promise things without promissing them outright, it just seems loopy to me. But it seems to be all the craze!

In a sane world:
Trim your game down to the minimum viable product, create a schedule for it, and then budget that schedule. Build a vertical slice of the game so that you can demo it. Now plan out the crowdfunding campaign to raise the rest of the budget.
Now add on some of the features that you would like to had, but had to cut in order to get a feasible MVP plan. Schedule and budget those features. Add them to the crowdfunding campaign as stretch goals.
Back in reality though, you've got companies making games with $3M budgets, asking kickstarter for $100k in order to prove to investors that market demand exists, so they can get their real investment... Meanwhile, your game $50k game is competing against those guys, and Joe Public is asking you why you need half as much money as Mr AAA over there where your game is only 5% the size of his...

Wow, it's clear that things have changed since I last partook in crowdfunding. I think I'll sit that one out, the work needed to even get in the door is better spent enjoying actually making the game, it seems!

Thanks for the warning signs, maybe one day in the future, who knows :)

Yeah, it's not easy anymore. Jupiter Hell which is the only game to date that John Carmack has backed barely met it's fairly low funding requirements to be honest.