Thanks for having this cool jam! I had been wanting to tackle doing an 18 card project, and this was just the nudge I needed to dive in.
Q 1)
For Viscera, I started out with the theme, which is often where I start with most prototypes. I knew I wanted to make a game about fleshly, amorphous creatures struggling to scavenge, grow, survive, and consume one another. I had a rough idea of what I wanted the card layout to look like, and I wanted to the art to be pretty visceral (organs, appendages, slime, gross meaty stuff), but my first step was to sit down and slap together some very primitive cards using freeware icons and some vector art.
This "bash it together and get it to the table" approach is usually my first goal in any prototype, because having cards and symbols and text to move around on the table can really help immediately identify design issues. It's good to have a sense of what the game mechanics will be and how they work together before putting any real time into art. I usually don't worry about proper art at all until much later in the design process, after I've gotten some good reps in with playtesting with various folks. Because this jam was super tight time-wise, I opted to just dive in full force and not playtest it as much as I would normally, because I fully expected to further develop it beyond the jam.
Working with only 18 cards and no other components is a huge challenge -- it sounds easy because there's less room for bloat in the design, but 18 cards is a pretty big limitation. I've played a lot of great micro games with 18 cards or less, so it's definitely doable.
With Viscera, I decided to have each card have multiple ways players could use them. To make this work, and simplify the visual design, I set it up so playing a card face up would focus on triggering its ability. Then, I put icons on opposite ends of the long side of the back of each ability card. By playing a card face down, and rotating it in one of the two directions, players could trigger a few different options (attack/defense, foraging for food). I also added a slight hidden information element to the combat mechanics...the ability side of a card has a number in the upper left corner, which represents the attack or defense power of a card if it's used for that purpose. There are also modifier icons beneath that number on some cards that give various bonuses depending on how you use it.
Combat encounters resolve after attackers and defenders have placed their cards they want to use for those purposes, but then all cards are flipped over and the numbers and bonuses are tallied to see who wins the battle.
In any event, finding creative ways to get more use out of each card was central to the design. I also used rotating and flippable card counters to track things like the player creature's body size and food storage. I think it all works fairly well, though I'm keen to further test it out and refine it.
Design-wise, things came together very quickly, but the art took the longest. I can average about 3-4 cards a day if I hustle and put a lot of drawing and coloring time in. That probably took up the most of my time during the jam.
Q 2)
In general I'm extremely happy with how the theme, the art, and the visual design turned out. For most of the 7-day development cycle, the rules and actual gameplay itself was a bit influx, and it really wasn't until the 11th hour that a few last minute changes brought it all together in a way that felt playable. Honestly, I'm happy with how the jam "alpha" version came out, but I'm absolutely planning to keep working on the game beyond the jam to refine it, test it, and sharpen it up.
Q 3)
The best part of doing a jam is it really forces you to focus and create something from start to finish in a very short amount of time. I'm a huge fan of rapid product development and making small, polished projects quickly (instead of big unwieldy games that take years to develop). Every time I enter a design contest or a game jam, it's ALWAYS with the idea that I'll use the jam to get an idea to the table as fast as possible and polish it as much as I can for the contest/jam, but the ultimate future goal is to fine tune and release each game I make in that way -- assuming it turns out.
I'm debating whether to keep the final version of Viscera only 18 cards, or boost it up a hair further to 36 cards instead. I like the idea of the game being very pocket friendly and replayable. We'll see what happens, but definitely keep your eyes peeled for a small Viscera Kickstarter campaign in the near future!
-Nathan