When comparing Pico-8 vs Moai, the Slant community recommends Pico-8 for most people. In the question“What are the best 2D Lua game engines?” Pico-8 is ranked 6th while Moai is ranked 8th.
Ranked in these QuestionsQuestion Ranking
Pro Perhaps one of the easiest sound editors around
Pro Encourages building simple games
As a beginner it's all to tempting to try to make the games you like to play, like Zelda or Call of Duty when we should probably be making pong.
Pro Share the game in a .png file with other pico-8 users
Pro You can read the code of any game you play
Pro Lots of examples
Almost every game made for the Pico-8 is open source (if you can download the .png, you can see the source).
Also there's the fancy Pico-8 "fanzine" that has lots of code examples as well as other great tutorials in a beautiful physical or PDF form.
Pro Easy to get things going very quickly
Pro Very simple programing language
It's lua with a few modifications.
Pro Takes away the pain of having to wire things together
Because it's an all in one product, you don't have to worry about things like how to load sprites.
Pro Helpful community
The Moai SDK Forum is active and users will go to great extents to answer queries, post code snippets, beta test, and even purchase and give feedback on each others' games.
Pro Helpful and detailed documentation
Although the Moai SDK is very advanced and uses complicated features, the documentation wiki thoroughly and clearly explains how to use these features, such as the Moai Cloud(a service that provides web services for your game), and multiple ways to build from source.
Con No collision library or other common things
Pico-8 is very minimalistic and as such doesn't come with really any abstractions whatsoever which means often you end up re-inventing the wheel.
Con Code editor leaves some things to be desired
Such as code completion and automatic indentation.
Con Costs 15$
Unlike many of the other frameworks it's not free. However this is kind of a feature because it means it's much more likely to be supported.
Con Memory restrictions could be confusing or frustrating to a begginer
Con Not for beginning developers
The Moai SDK has very advanced features which allow it to create powerful games. A drawback from this is that it is not very suitable for beginners.