When comparing Roblox Studio vs Solar 2D (formerly Corona SDK), the Slant community recommends Solar 2D (formerly Corona SDK) for most people. In the question“What are the best 2D Lua game engines?” Solar 2D (formerly Corona SDK) is ranked 2nd while Roblox Studio is ranked 11th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro It's easy to use
If you want to find an object in the workspace just use workspace or game. In Unity (for example) it's much more complicated.
Pro Easy multiplayer
Multiplayer is set up on project load.
Pro Easy to use for children
It's the entrance to game development. But it will be likely, that you abandon Roblox as soon you turn old enough.
Pro AI Scripting
Pro No serverhosting required
Pro No website needed
Roblox hosts a very basic website to play your game for free.
Pro It’s fast
Scripting can take maybe only 30 minutes to get some real work going while others take hours.
Pro Very simple to use
Pro Free
Corona SDK is completely free. That includes pro-tier plugins.
Pro Corona Simulator
Corona SDK ships with Corona Simulator, which runs your game/app directly on your PC/Mac and updates every time you make changes.
It provides immediate feedback to your actions, you can see your changes right on the screen, without necessity to make build to device. Getting instant feedback really boosts tenfold prototyping and development speed.
Pro Good documentation and lots of tutorials
Pro Content scaling
It's easy to create a game that looks good on many different sized mobile devices.
Pro Live builds - update builds running on a device automatically
With the live build feature, once you have created a build and installed on a device, you get lightning fast turnaround times because any change on the code or data is updated to the devices running the game (within the local WiFi) immediately. So changes can be tested on the real hardware within a very few seconds.
What's even more impressive, this even works flawless with multiple devices running the game. You have to use it to learn how good of a feature this is while development and even more, while doing QA. Imagine fixing bugs and everyone of your QA team/friends/whoever helps to get your game done, has all changes on his device without doing anything but waiting 5 seconds - outstanding.
Pro Lua syntax
Uses the great and easy-to-learn Lua programming language.
Pro Very comprehensive API
It's very quick to get things up and running with Corona SDK. The API is extensive and while it's not 100% feature-complete with the iOS API, it's close enough that you could create tons of games and never run into a roadblock.
The API docs can be found here.
Pro Amazing learning curve
Corona does not throw photoshop-like madness full of buttons editor. You can go as fast as you want, learning and building game from ground up. Eventually, you'll learn how much corona is doing for you. But to start you don't have to master complex editor software. It's a great tool to learn to start game development if you want to learn how to program and make games. Your experience will be 100% transferable to any other Pro game engine.
Pro Cross-platform desktop and mobile
Corona works on OS X, Windows and Android (including Kindle Fire & Nook).
Pro Marketplace for 3rd party plug-ins
Pro Great community
Pro Ability to call any native (C/C++/Obj-C/Java) library
Pro Completely free
Since Corona SDK became Solar2D, it's completely free, as only some third-party plugins are paid.
Pro Open Source
Since Corona SDK became Solar2D, it's completely open source under MIT license.
Pro Well supported
Cons
Con No support for Linux
With the new-Bit client, Roblox went out of their way to make it impossible for Linux users.
Con No tutorial system in place to teach new dev's the basics
Con Can only be published on Roblox
You can't export your game to Steam, Epicgames, Snapcrft or Flathub.
Con "Potato Servers"
Roblox Servers aren't that good in performance. Also, a server can officially only handle 100 players at the time. They tried 200 player severs, but abandoned this idea.
Con Players need to be online at all times to play your games
Con Can't selfhost servers
You can only use the Roblox servers.
Con Can't post links in games
The Roblox TOS only allow Links to certain platforms like Guilded.
Con High tax rate
Be ready to give 75% of your earnings to Roblox.
Con Bad moderation system
Con Free, but not completely
Con Making a device build requires internet connection
To build your app for the device (iOS/Android/AppleTV) Corona requires to fetch resources from online. This would include base application template and plugins. This allows not to perform local build or use Xcode or Android Studio to do a build. Even Large games/apps would build very fast with good internet connection.
Your code never leaves computed. Corona SDK would transfer some information to determine which plugins and pieces has to be transferred in order to make a final steps in build.
As a bonus - you get basically one button press to get from your Corona Simulator game to game on a device.