It depends on what grounds you want to compete. The gaming world is actually many parallel worlds. The platform and price of the product defines people's expectations, and people judge differently when faced with a different world. A commercial game they'd boo, they'd woo as mod, same for an Xbox360 game and a Nintendo DS game. Even today, many of the most popular mods and indie projects have very simple graphics. That does not mean they are ugly, though some of them are, and still exceedingly popular. Using UDK does not mean you have to use it to its full extend to become popular. People may not even know how the game was created. Most really don't care to know.
Curiously, in practice it mostly goes the other way around, most of the more ambitious mod/indie projects are unsuccessful. Part of the reason is that too much dev time was spent on things least significant to success in this territory, like complex visuals. Of course such thing can be a bonus point, but not when it comes at penalty to other things, and if you are not heavily funded, most likely does.
Furthermore, the platforms with the greatest growth for gaming are handy/handhelds sections, which of course are far more limited by default, doesn't impact popularity though, as it makes up with other platform qualities, and as long as prices are right.
And then flash games. Yes i know. But it's there and it's big. Quick, dirty, convenient, omnipresent.
A feasible and very successful approach might be doing mods "multi-platform". Imagine doing a simple flash game that shares the most basic idea and style of the actual and much more involved mod, and easily circulating that flash game for good promotion. Probably dev time much better spent than killer graphics.
On another note, this is the real but mostly unknown reason why Apple's new iPad does not support Flash, rather html5. Publicly they argue about watching movies and it being too old/buggy/security risky/performance hog for that. But the real reason is outside of movies. While html5 on paper is better for movies, it is comparatively limited for complex interactive programs and games. See now what Flash would undermine and even threaten? Bingo, their App Store, their absolute, and absolutely profitable, distribution portal control. So they rather talk some bullshit points and pressure the rest of the world into adapting to their needs. Because they can.
Wut ohne Ziel. Wut ohne Folgen.