I’ve been lurking around this thread since it was created, and I’d wager some of the guys from the other larger teams are too.
One reason it’s hard to find cold hard facts is because quite often distribution agreements contain clauses preventing the publication of sales and financial data. Some Indies do breach these clauses from time to time and post sales data on gamasutra reporting on the impact of sales promotions. Another reason is that often full-time developers are too busy taking care of their business, skim-read forums for useful information, and post less frequently.
From what I’ve seen if you are a talented solo developer, preferably with a low life-cost base, you could fund yourself full-time via the asset store, or freelance commissions. Having a visible product in the asset store would certainly help with the latter. That is one form of success. Alternatively there is mobile - shorter development lifecycles and costs with direct market access are the main reasons why developers flooded to the channel. Zombieville is a great example of mobile success. I’d wager however that it’s become far more difficult now to be a success in mobile due to saturation.
For larger teams, larger budgets are required, and unless a team secures a meaningful global distribution deal it’s going to be very difficult to make the sales required to make the game financially viable. Before a team gets to that point, they’ll need to have at least some funding in place raised either privately or via crowd funding, and that has it’s own quality bar that needs to be achieved acting as a barrier to entry.
The title of the thread mentions financial success, but further definition is required. Large and well known studios can shift large volumes, but net profit ( lets use the rudimentary revenue minus costs measure rather than say EBITDA ) can end up negative resulting in their demise if it’s a multi-year trend. A solo developer can make more net profit than a large corporation in a year, and on that basis could be considered more successful.
Are there success stories around for teams using Unity? Absolutely. But success is not black and white, and only in the medium term ( 5-10 years ) can their success truly be measured. An increasing number of titles on Steam Early Access are developed using Unity: Folk Tale, KSP, WFTO, Castle Story, Godus being five examples. For these titles worldwide revenue ( inc. Kickstarter ) will have been significant; certainly enough to make development financially feasible. Perhaps the best known title using Unity by an renowned studio is Hearthstone by Blizzard.
This is a Golden Age for Indie developers. Is it easy? Heck no. It requires funding, talent, creativity and experience in multiple disciplines - not just game development - to produce a high-quality market-relevant offering, maximize commercial opportunities, and to ensure financial stability throughout.
TL;DR - Yes.
