The second game is the ultimate version that Rogue Legacy 1 should have been, and I say this with a lot of love and hours into the first game. It takes everything from 1 and turns it up the maximum and then some.
It's been over 10 years since we released Rogue Legacy 1, and in the pursuit of sharing knowledge, we are officially releasing the source code to the public.
Rogue Legacy 1's source code is made available under a custom license. Basically, you can compile yourself a copy, for free, for personal use. But if you want to distribute a compiled version of the game, you might need permission first. See the EXCEPTIONS.md page for more information.
I guess the main benefactor will be the modding scene. Indie devs can make deals with Cellar Door Studios to get a commercial licence with additional conditions. It might be close to open source in practice if the commercial licences are handed out generously.
Just to clarify, licenses are free software or open source when they fit the definition of those terms, aka the 4 freedoms and whatever open source requires, but both require being able to use the software without restrictions. So this isnt open source.
Honestly? They're probably going to continue to offer the game on Steam and it will probably continue to trickle in revenue. Most people who are interested in the game have already bought it, so it's never going to draw in millions again.
The game is currently listed at $15, but goes on sale frequently for $3. I bet many new players would be happy to pay steam $3 for the cloud save and steam's easy game management, as opposed to compiling from source for every new PC install.
Finally, the gameplay loop between Rogue Legacy and Rogue Legacy 2 are pretty similar. This means the the original is a good extended demo for the sequel which is .$25, but up to 50% off. Frankly, it's a great marketing move at this stage in the game's lifetime.
The source code being available doesn't allow you to play the game. To actually play it, you'd still have to buy the game. Unless you figure out how to play it without any artwork.
The assets aren't free and open source. If you want to legally use the open source code to play a game, you'll either need to buy the game to get the assets or use an alternative like freedoom.