It was bite-sized in terms of how long it took us to create most parts of the content. Not the art, or the puzzles -- those did actually take a while. But in terms of the main form of the replayable content in particular -- all the special items and so forth -- that was all just design work and some lighter coding. It's a lot easier for us to work with pure design issues rather than having to, say, invent a new form of lighting model that works in our specific 2D implementation, or port a game to a completely new underlying engine, or come up with an entirely new way to composite images for efficiency, or design a new GUI system from the ground up, or a new multiplayer model from the ground up... etc.
This time we have all those things already, so it's just a matter of using our existing tools and focusing on making something with a lot of depth and replayability. The idea is deep rather than wide. Valley 2 had 200 spells and 125+ monsters. That took aaaaages. The amount of art required, and the amount of coding and tuning, was enormous. Comparatively, the 20-some blocks and 20-some game modes here seem lightweight. It's a tremendous amount of replay value, but it's not remotely so intensive for us to create.
From a programming standpoint, the reason Tidalis was so expensive for us to make was that it was our first unity game, and that involved huge amounts of overhead and months of programming. The actual game itself was pretty lightweight. The art was also a pretty heavy thing in terms of time cost, but we only had one artist working on it. Versus Exodus has currently... I think six artists working on it? The number fluctuates. Skyward Collapse currently has 8 IIRC.
Music is something we'll still be constrained with because we only have one composer, but he's doing different workflows now that allow him to get more done in less time. Not like double the work, but definitely more. There's only so much you can rush inspiration, you know? In terms of the design aspects, we're not really doing that any faster or slower than we ever have, speaking of the new games. The design work feedback loop is just faster since there's not such big delays based on programming it in.
Basically, Arcen has really fine-tuned the machine of creating a wide variety of types of 2D games, and so we're making use of that and also passing the savings on to players.