Depends on what you want to do and why.
A game running in Gaikai is pretty much still the same game that ran on your local console. Its FPS may be bumped to account for network latency, but that's pretty much it. The input/output now work over network and not over HDMI/Bluetooth to your TV/Controller.
A game that runs locally but offloads parts into a cloud is a completely different beast entirely. Such a game is a time-critical distributed software system and, thus, much more complicated. In fact, most of its subsystems cannot be "offloaded" by any practical means. Latency and bandwidth are natural barriers, and the inherent unreliability and asynchronicity of distributed software parts make the developers life a pain in the ass.
And the parts that can be "offloaded" are most likely those parts that are already done on the server-side in multiplayer games and MMOs, that is, game world synchronization and shared gameplay elements like bullet impact calculation.
In addition, it doesnt make much sense economically to (a) build expensive dedicated local hardware like the Xbox 180 APU and, in addition, run an expensive cloud infrastructure to run non-essential functions like visuals. No developer would do that. They would just scale the game such that it runs entirely in the local hardware. Less effort and fewer costs. Cloud infrastructures make only sense for functions that are inherently in need of servers (multiplayer, MMOs, sharing, social) and define the product.
^This guy probably put it the best.^
The issue was MS originally saying ZOMG TEH POWAR OF TEH CLOUD BETTAR GRAFIX BETTER AI
Realistically, there's very little a cloud service can do to augment a game beyond the stuff we already have this gen. The examples we've actually been given of Teh Powar Of Teh Cloud have proven that:
For Titanfall they have said that Teh Cloud allows them to have NPC AI characters actually calculated server-side and implemented in game seamlessly. Translation: Since the game is running on dedicated servers,
congratulations, they've implemented a server running bots. We've had that since... what, QuakeBot?
For Forza 5 they have shown that the game uses Teh Cloud to remember exactly how you drive; how aggressively you pass, take corners, how you hit your apexes, etc. Then your friends can race against the cloud-based AI drivatar even when you're not online, and your drivatar can win races for you! Translation: Your locally created drivatar is uploaded to the server where your friends download and race it, with their console doing all the AI calculations based on the parameters of your drivatar. At least, we *hope* that's what it means, otherwise they will be (hilariously) streaming a multiplayer AI car with all the lag that entails, when it can easily be done client side.
This is not exactly the groundbreaking cloud nonsense the PR mouthpieces were talking about, because that stuff isn't really feasible.