So few Mac games make it down the transom that I do take note when they show up on Steam's list. Ultratron was one of them, though I didn't buy it because it didn't seem like something I'd be into. Whether or not the game deserves to be a blockbuster, it indeed stinks when hard-working developers don't have much of a net or runway to finally craft the next big indie hit.
That said, there still seems to be opportunities to break out for developers of all sizes. Recent success stories that come to mind:
* Faster than Light, a space sim just made for Star Trek fans...it reached $200K on Kickstarter -- 2000% of what they had initially asked for -- and it still seems to be selling well. I just bought it last week and it has ruined my free time (http://www.ftlgame.com/)
* Block Fortress - a ingenious mishmash of MineCraft, first person shooters, and tower defense. These developers (apparently, four brothers) also made the great Heroes and Castles, a first person tower defense game. And both of these games are dirt cheap with totally reasonable/optional IAP: http://foursakenmedia.com/
* Ridiculous Fishing - a casual iOS game made by some all-stars of iOS development, including Vlambeer and the guy (Zach Gage) who did the awesome SpellTower, one of the iOS games I've played the longest: http://www.ridiculousfishing.com/
* 10000000 - A match-3 dungeon game for the iOS that the creator made in his spare time as a labor of love...it caught fire when a TouchArcade editor discovered it. Addicting as hell: http://toucharcade.com/2012/08/01/the-toucharcade-show-bonus...
One of my favorite dev reads from last year was "Starcraft: Orcs in Space go does down in flames" (http://www.codeofhonor.com/blog/starcraft-orcs-in-space-go-d...), in which the Starcraft dev talks about how a completely faked game, Dominion Storm, forced Blizzard to reboot Starcraft (for the better)...the game was faked at E3, where companies spent hundreds of thousands of dollars just to secure floor space and throw big BS publicity stunts, because that was the only way to get press attention.
At least today, as a developer, you have options of getting yourself known and your work seen without having to jostle for floor space with the big boys.