Just to clarify your comment - the Moai engine supports isometric (2.5D) and 3D functions for effects. Shadowrun Returns, a 2.5D title, is being developed with Moai. See http://getmoai.com/blog/thinking-isometric.html for an overview.
There is no license restriction on Moai as noted. It's a standard CPAL license, approved by the Open Source Initiative. CPAL itself is a derivative of the Mozilla license. http://getmoai.com/moai-faqs.html
Thanks for noticing! I work on Moai. Our goal is to enable game devs to build great games, and to do that today you definitely need an online component. Our differentiation from other services is (a) Moai is designed for games, not generic mobile apps and (b) you can write and run your own code, in a gaming friendly language, which enables you to innovate on game features.
Moai Cloud can work with any front end SDK. We do have several Corona and Unity devs building game back ends on Moai Cloud. Robert Nay, the poster child for Corona, is one of them.
Thanks for your kind words about Moai. Considering we only shipped 1.0 last month, it's exciting to see how quickly game devs have connected with the idea of a minimalist open source framework + cloud services for games.
Unity is a fine product as well. We have a number of Unity developers building their game back-ends on Moai Cloud, and we are working to build more features for them.
I work on Moai - we just shipped 1.0 last week. It's designed to be a minimalist, open source framework for game development. We think that's the best approach for experienced game devs - look at Bungie's Crimson Steam Pirates on iOS and Chrome for an example of what you can achieve. If you need a higher level scene manager, then check out Rapa Nui for Moai at https://github.com/ymobe/rapanui