Steam trading card ideas?

So, as you might now, I'm not actually that much into neither achievements or trading cards 'n such. That is, not when the achievements are granted for playing the game in a regular game (e.g. "congratulations, you just beat the game"). In Knytt Underground, I still wanted to have achievements, but unusual ones for finding secrets and getting to strange places.

Now, I hear it's good business to have trading cards for a Steam game because lots of people are into that stuff, and I want to add them in a way that's funny but doesn't distract from the game for those who doesn't care about them. Do you have any interesting ideas for how cards should be obtained? Also, what motives would you like to see on the cards? I can have characters, but I'm also ready to go nuts and put random nonsense on them

Normally the cards just are being given if you play a certain time.

I guess I would tie those cards to major achievements in the game, preferably secrets, but I guess ringing the bells could also work. Maybe 2 to 4 cards for in-game progress, and 4 to 6 cards for secrets?

As for what to put on them, I'd use things that are already in the game. Could be objects that you collect during the quests, but also important items, such as dimension crystals, coins, and even characters, such as pixies, fairies, etc.

An alternative could be various locations. Hmm... If you can add to the game at this point, it would actually be cool if putting all cards together gives you a map with a hidden, really hard to find, secret. Like a map with a direction on how to travel in order to get to this secret. Wouldn't that be awesome? and of course, you can only complete the secret if you have all cards.

Okay! What more specifically would you like to see cards and badges of?

Edit: Hey, maybe the badges can be human items (other than the ones in the game), labeled after the sprite's guesses of what those items would be. Any ideas for artifacts?

I had no idea developers had control over trading card dispersion! In every game I've played I just slowly accumulated four through building up playtime.

Nifflas didn't have a good idea of what this is either, but after the chat we had, he now has. I still don't know if he can decide when the cards drop or not, but he seems to understand the concept now. All we need now is ideas for a card set and maybe 5 levels of a badge.

Small info on trading card principle: You have one set of cards per game. Once you have all the cards, you can trade it in for a badge. If you collect a 2nd set of cards for that same game, you can upgrade your badge. You can upgrade a badge in total of 5 times.

I did a little research and it doesn't seem like there's any precedent for awarding cards based on actual tasks, just random drops? If that's so, you might only have to worry about how many cards to have and what to put on them.

Probably the most conventional subject for the cards would be characters from the game. An idea that appeals more to me would be locations from the game. Human artifacts is a good idea, not sure if it's too disconnected from the game itself, though... do these cards have to go through some kind of approval process?

Some things off the top of my head other than characters would be the bells, The Figure, maybe Dr. Cliche's lab... That's all I got.

Bells and Human Artifacts, of course.
and some memorable area? like Ljus, Shadowlands, Utopioca, ...etc.

I've learned that badges are a thing too! You should make them look really cool since they require the destruction of all your cards. I find this whole system pretty silly, but it might be nice to have just one badge.

I can offer much info on this, since I spend most of my gaming time on steam and love to collect badges and achievements.
Here is my profile page, feel free to add me!  http://steamcommunity.com/profiles/76561197993146044

Devs cannot specify the method of trading card drops (although this may have been changed by now..?); they drop regularly during time spent in-game (usually an hour or two each) and each account may only receive half of the total number of cards for that game.  If you can now though Nifflas, I recommend keeping it this way, rather than rewarding them for game completion events, since the achievements are for that anyway.  However, they can obviously decide the number to have.  You may think the more cards a game has, the more profit the developer will make, but unfortunately increasing the number decreases the value of each one (since more drop for the players).  There are usually 5-10 cards per game at prices of 15-50c each, depending on the game's popularity.

Badges work as LP Chip says, but the set of cards stays the same (so Nifflas only has to design one set rather than five).  Foil versions drop at a rate of 1% and can form a badge of one level only.  When you craft a badge, you receive a random coupon for another promoted game, a background and an emoticon that pertains to the game.  This means Nifflas will have to design (or get people to design) backgrounds and emoticons for KU!  Having said that, I highly recommend using game locations for backgrounds (Ljus etc.) and characters and/or items for emoticons, and I suggest having 5 of each (3 common, 1 uncommon and 1 rare is the norm for indie games).  I also like the idea of having artifacts as badges (and maybe for the foil badge?)  Trading cards can, however, be random and include examples of different types of things in the game.

I hope i've helped somehow...
Really looking forward to this!

Thank you for all this information