End of September I flew to Poland for Pixel Heaven Indie Gaming Fest which Karaski was a finalist at. I showcased the game at a small booth and made many mistakes. Here's what I learned.
Ask Press for cards, email a "thank you" and game copy
Early on I was interviewed by two journalists, but in the fervor of barely arriving and scrambling to set up I forgot to ask for cards! What a novice mistake. Emailing a simple Thank You with a press copy of the game would've been the right way to foster a good relationship. Silly me.
Give out flyers, don't just have them lying around
I quickly realized many people were hesitant to reach out to grab a fliers, so I started giving them out even if unasked. Sure, most of those who didn't ask will probably toss them out or use as emergency handkerchiefs, but one or two might decide to give it a second look at home and check out the website.
Put up a newsletter signup sheet, encourage people to sign up
It may seem old fashioned, but it is the most direct way to get an opt-in audience instantly. Flyers require people to recall what the game was about, type the address in, re-judge their interest, and finally click on subscribe. Simple signup cuts all these steps out!
Actively invite passerbyers to play or hear the pitch
Many will be on the fence to stop, with so many awesome games all around, so a friendly nudge is sometimes all they need to turn the hesitation into keen interest.
Wear an official game shirt or some indicator
Since I was dressed casually, many people did not realize I was actually the dev showcasing the game, so they were hesitant to ask questions if I wasn't already babbling about it.
Showing Your Game
Bring a controller
Playing Karaski on mouse and keyboard might be what it was initially designed with, but it was not optimal in an expo setting. The small booth felt a little cramped, and a hunched-over person prevented others from seeing the screen. I was also surprised just how many gamers were unused to traditional FPS keyboard controls as well.
Consider renting equipment
Some expos (such as PAX or GDC) can facilitate equipment rental. Showing off your game on a huge screen with quality speakers might make it all that more intriguing. If the budget allows it, of course...
Prepare a demo level
if you can and have time, create a demo level that has all the juiciest gameplay bits with a built-in tutorial. For my open-ended story-driven game, loading a mid-game save did the job pretty well!
Put up controls cheat sheet
Seems obvious in retrospect - people playing a complex game don't know how to control it! Re-explaining controls gets tiring, and playing the tutorial isn't always the best way to showcase your title (luckily, in our case it wasn't a bad choice either).
Put up a story/premise cheat sheet
Similarly, a simple 1-paragraph pamphlet with pictures or even a comic to explain the game's promise would've been useful. I've repeated my 30-sec elevator pitch so many times, my voice was dead by the second day. People prefer to listen, sure, but I still think it would've cut down on needed babbling.
I'm sure there's a thousand more little nitpicks and ideas you could think of to maximize your exhibit, but those were the most "glaringly stupid mistakes" I made. Half of these seem obvious, and yet I didn't consider them until too late. So be smart and learn from my mistakes :)