Lua vs C#

One of the best features of Lua is its very well designed C API. This is very useful if you have an existing C library you need to integrate with Lua or quickly get a Lua script running on the C side of the game.

Finally Lua plays so nice with C that if you need to optimise for speed you can re-write it in C a lot easier than other languages.

The official Lua documentation is very helpful and thorough. There are also a large number of online resources or books with lots of helpful information for beginners and advanced users alike.

Lua can be built on any platform with a ANSI C compiler.

Other than that, Lua is extremely small. For example, the tarball for Lua 5.2.1 is only 245K compressed and 960K uncompressed (including documentation).

When built on Linux, the Lua interpreter built with the standard libraries takes 182K and the Lua library takes 243K.

The small size and the ability to build with a C compiler make Lua an extremely portable language that can run on a lot of different systems and computers.

Easy to learn.

Lua's performance compares very well to other languages, If performance needs to be further improved you can:

1. Implement critical parts in C
2. Use the LuaJIT compiler. The LuaJIT compiler is a drop in replacement for the stock compiler and provides significant performance improvements. From the overview page:

LuaJIT speeds can rival code written in C.

Many different game engines (e.g. Elder Scrolls series, ToME) use Lua for scripting, and it's runtime is designed for embedded use.

The Lua syntax is modeled from Modula, a language known for being a fantastic introduction to programming.

The Lua syntax also has the following key characteristics:

• Semicolon as a statement separator is optional (mostly used to resolve ambiguous cases as in a = f; (g).x(a)).
• Syntactic sugar for function calls (f'string', f"string", f[[string]], and f{table}) and method calls (obj:m()).

Due to the growing popularity, Lua has a rather large and helpful community surrounding it.

.NET offers rich functionality.

The Visual Studio IDE offers one of the best development environments. The Community Edition and Visual Studio Code can be used for free.

Can be designed visually with the Visual Studio designer for traditional Windows forms, WPF, or Web forms.

Lot's of tools and libraries available.

With Xamarin for Mobile (ios, android),
with .net core asp for server (linux, windows),
with .net core for desktop (windows, mac),
with mono for desktop (windows, linux),
with blazor for web client with webassembly.

However, it is not considered top for any of those categories, but it is top choice for Windows desktop with .net framework and top choice for Unity.

.net 5 will unify frameworks similar to JVM (just one).

Runs on Linux, Mac, and Windows.

Constant updates and bug fixes to many popular frameworks, as well as great first-party support from Microsoft. This can be a con as well in certain circumstances.

Being a C like language counts in favor for it as a general purpose programming language, given the ease of using existing skills to pick up this language easily.

There are other superior languages that could be used as a general purpose, such as: F#, Haskell, but the complexity of those languages, being functional, make them strange to the usual C Syntax.

C# is better than C whenever garbage collection, Objects, classes, data access, are needed. But C is going to be the choice when hardware access and performance are paramount.