Allow me to present a possible counter opinion to the argument that creativity is born from limitations. The overall idea is that complacency and ineffectual pruning of superfluous elements have lead to the uninspired, yet, cluttered, designs of many modern games. Imposing limitations forces away complacency and necessitates reduction. However, the resultant creativity is not caused so much by the limitations as the increased discipline of the creator to focus more on the quintessential nature of the game.
It is not strictly the limitations that breed creativity; rather, it is the self-imposed discipline to remove the superficial distractions that prevent us from perceiving, understanding, and exploring the quintessential nature of game-design that breeds creativity. In some sense, the advances of technology have imposed more restrictions because of gospel-like design requirements(multi-player, particular special effects, "like GTA but...", etc.) that are imposed on projects that may or may not properly fit the context or flow or the original game vision. As a result, the true vision and inspiration of the game becomes clouded and distorted by these imposed requirements. Some of these requirements are removed as an artifact of limiting oneself to retro-games and, thus, removing the clutter that obscures the creative vision of the game.
By imposing some limitations, we remove complacency. By having a number of formulaic tools and features that have known success, it is easy to become complacent in the use of these elements without understanding how and why they worked in the various contexts under which they were developed. This complacency leads to a sort of blind drag-n-drop mentality in the construction of modern games. As a result, despite actually having more freedom, because that freedom is taken for granted, there is less creativity in modern game design because there is less effort placed on understanding the principles and mechanisms that allow a game to function in a given context. By imposing limitations on the available tool-set, we force the creators of games to put more effort and thought into the fundamentals of game design and presentation.
It is entirely possible to have a very creatively derived game using the modern tool-sets, features, and technologies available. However, doing so requires discipline to not be distracted by the superficial results of those tools and focus on the essential vision of the game and how to realize that vision through the tools available.
Additionally, there is also the discipline of realizing when the work is becoming too cluttered by the inclusion of too many elements that don't fit together and throwing out the superfluous elements. One of the biggest problems of many artistic and creative types is falling in love with every possible idea and concept that can be crammed into a work and being extremely recalcitrant to throw away elements that just simply do not work with the rest of the work or are incongruous to the original vision. The eraser is perhaps the single most important artist's tool, and the artist should never be afraid to use it.
Personally, I've found that with creativity, one thinks of everything all at once, to start. Then one goes back over the work to start throwing stuff out that doesn't work or clutters things up. However, the advances in technology and efficient techniques have lead us to feel less compelled to throw things out. By imposing the retro-gaming style, the developer is forced to throw things out, resulting in a more essential creative work. However, the same effect can occur with some simple discipline.
Limitations do force the need for adaptations, which is a driving force for creativity. However, the motivation to evolve and adapt can by self-inflicted by choice rather than imposed by limitations. This is, again, a matter of self-discipline to avoid complacency with current accomplishments and continue to push at the boundaries. But in so doing, to realize that it is not a matter of including more elements into a work; rather, it is a matter of trying to coming closer to an understanding and perception of the quintessential nature of the work through exploration of self-consistent possibilities.
Limitations force the issue of needing to adapt and reduce superfluous or incongruous elements from the work. However, limitations are not a necessity to achieving this end. The discipline to focus more on the quintessential nature of the work is a more essential factor to achieving this end. Granted, limitations can force the awareness of need for such discipline, however, this discipline can also be chosen rather than requiring external imposition. In this manner, limitations breeding creativity is more an artifact than the true rule.