Actionscript vs Nim

Easy 2D and rich 3D capabilities means ActionScript is a great game prototyping or production tool. Relatively easy to get images on a stage and easy to share with it's wide platform support.

Runs on all major platforms as an AIR executable or mobile app, as well as in-browser as a FLASH file.

Teaches strong typed habits and follows many conventions of major programming languages.

Online games and a colorful history means there are a lot of existing scripts and examples on the internet for available integration as well as tutorials.

There are generics, templates, macros in Nim. They can allow you to write new DSL for your application, or avoid all boilerplate stuff.

Checks your code at compile time.

Nim has a lot of common with Python in terms of syntax. Indentation-based syntax, for/while loops.

You can use Nim with any language that can be interfaced with C. There's a tool which helps you to create new C and C++ bindings for Nim - c2nim.
Also, you can use Nim with Objective C or even JavaScript (if you're compiling for these backends).

You don't need to deal with all those manual memory allocations, Nim can take care of it. But also you can use another GC, or tweak it for your real-time application or a game.

Nim has a built-in VM, which executes macros and some other code at compile time. For example, you can check if you're on Windows, and Nim will generate code only for it.

The same code can be used for web, server, desktop and mobile.

You can use unicode names for variables, there is "unicode" module for operations with unicode.

You only need to specify types in your procedures and objects - you don't need to specify type when you're creating a new variable (unless you're creating it without initialization).

Imperative, OOP, functional programming in one language.

With built-in "unittest" module you can create test with a very readable code.

writeLine(stdout, "hello") can be written as stdout.writeLine("hello")
proc add(a: int): int = a + 5 can be used like 6.add.echo or 6.add().echo()

Nim has "asyncdispatch" module, which allows you to write async applications.