This post is about my opinions on the presentation and quality of games. It is ranty.
Give It A Good Title
I am deadly serious here. There is nothing that will stop me from buying a game faster than a title that's deliberately constructed to be a boring or nonexistent word when acronymed. FATE, GURPS, CODA, S(Where is the W?)ORD, &c., all come to mind here. Why are you obscuring the game's name behind its initials? Is it that bad? Yes, I know that it is. Stop doing that.
If you want me to buy your game, its title better tell me something about it, or, better, raise a question about it. Don't be too verbose; we are young and fearless and have no time for that. Don't tie yourself up in someone else's conceptual space*.
Take great care when punctuating your title.
Woozly fantasy words with interspersed punctuation and caps don't cut it, either. HârnMaster? Secret of Zir'An? Who are we here? Okay, I'm a linguist. I like my words to be mangled systematically.
If you are extending a preëxisting property, then please come up with a new, related title for it. I am doubly likely to give something a second look if my first impression of it is pleased surprise at the depth and cleverness of your scholarship! Thus, until someone writes Quentasta Aratar of the First Age of Middle-Earth, I am not buying a Tolkien game.
Stay Away From Cheesecake
By which I mean, "I should be able to read these books around my parents." This isn't so much a self-consciousness thing as it is a subject-matter thing; if I want to look at big excited boobies I will locate an appropriate website, thank you.
State and Meet your Design Goals
Really, people. Just, like, demonstrate that you know you're a craftsman and you understand your craft in a workmanlike fashion. It's not tough.
Get Me Going
This is, like, probably the toughest bit here, because there are several ways to do this and they're all kind of interrelated.
Presence
I won't know about your game unless you tell me! Similarly, I won't look at your game favourably unless I like you. This means, like, advertise your game, be enthusiastic about it, but don't let it override your personality. Be an interesting person in your own right, or else don't have a personal presence at all! It's better to be a faceless designer than it is to be a shill.
Particularly, make a habit of taking critique with good grace. Communicate with it, learn from it.
Beauty
Okay, so I have tastes, and this is where those come out.
This becomes less useful as advice to designers who want their games purchased at all, and more useful as advice to designers who want their games purchased by me. I realise there are not that many of you out there.
Characters. Games tend to have characters! If you do, then they should not be losers, or at least not unmitigatedly so. I am not really interested in telling stories about losers. I tend to like it when characters have abilities that surprise and amaze me, but this is by no means mandatory.
Settings. I like it a lot when cosmologies are self-consistent in some manner. They don't have to be logically consistent with the world if they are not literally true in the world, but they do have to have some mythological element of making sense. Yeah, I know that's a really weird statement. I also have standards for linguistic plausibility! Fictional languages contain many pitfalls. If you're going to use them, then put some linguistically-aware thought into them. Come up with a systematic, meaningful orthography. Concern yourself with syllable structure! Most fictional languages will end up being naming languages, so you don't need to go into syntax unless you really want to. It is often a better course of action to simply sidestep the issue by using an appropriately resonant natural language.
All this talk assumes a fantastical setting. Yes! For my part, I am not overly interested in "real world" settings. There's a lot of baggage there that I'd rather do without.
Systems. This is mainly for another post. Just one tidbit: If the system goes into detail about some facet, then I, as a player, want some influence over that detail. I want the power to make decisions about it.
Appearance! Holy crap! Don't lay out your book like it is ugly. C'mon now, you know who I am looking at. HeroQuest. Dungeons & Dragons 3e. Torment my eyes! Did you seriously pay people for those readability disasters? Why? Take some notes from Engel, but don't let your layout excuse bad systems writing. d20 Engel? I am looking at you. It really pays to have a nice logotype and a clean, expressive cover graphic. See Nobilis.
*: This is the great downfall of With Great Power..., which always makes me think, ...comes great fucking Spiderman. I really don't like Spiderman. Of all the superheroes that I don't like, I like Spiderman the least.