The C4 Engine is a comprehensive suite of professional, robustly implemented game programming tools for PlayStation 4, Windows, Mac, and Linux.
I've been working with this engine for almost 2 years and love the code base. You do not need external libraries like stdlib or boost and nothing is hidden, so in the rare case that bugs are encountered, they are found and removed by the engine creator almost immediately.
Great engine and fast service in the forums.
It is October 2014 and C4 Engine has reached version 4.0. This is the biggest update in its history and its selling for an unbeatable price, so I thought I'd update my old review.
The new demos look fantastic and show what can be done by a two man team. The new island level is great and the cemetery level is particularly impressive. If you like isometric style games like I do, get yourself killed in the island demo and it will let you fly around it. That way you will see the engine runs well, from that viewpoint as well.
The physics has been improved and the world manager has been reworked, so the more nodes there are in a world, the better it performs.
The visual scripting has several improvements, the most important to me, is being able to run multiple scripts from the same script and the addition of the Activate Trigger and Deactivate Trigger methods.
The world editor has been improved, with all tools arranged in 5 tabs and the new gizmo is very, very, nice. A couple of new tool pages have been added, including one that manages both node selection and visibility and a node finder page, both of which are must haves.
There are many other improvements, described in the release notes for 4.0.
I'm still enjoying using this engine very much and wouldn't use any other. I have added Recast Navigation, Raven AI, a HTN planner, a ton of my own code and everything is rock solid and compiles quickly. The service in the forums is excellent as always and the current price is a world beater, so I suggest everyone check it out.
I've only been working with the C4 Engine for a while now, but I've had enough experience with other game engines, to tell you what things made C4 the obvious choice for me.
Integrity - Refreshing to see an engine tell it straight about needing source code access. Anyone saying different is telling half truths. Period.
Cost - Reasonable price, forever, no upgrade costs, no royalties to further constrain your budget! Depending on your license type you can even have small features added or problems solved for your own needs. For simple problems Eric or the community will normally help over the forums.
Support - Eric is terrific, I can't say this enough, timely responses to questions/problems, new features and bug fixes regularly worked on. A professional and mature community offers its support as well.
Architecture - The design, and the clean thoughtful approach taken to implementing all its features makes understanding and working with it an enjoyable experience.
Features - Regularly being updated, the roadmap shows the few features missing that contenders offer (SSAO, HDR) are being implemented, plus it offers a some things you will only find in C4 like Transvoxel Terrain, Horizon Mapping for example. Being able to request small feature additions, and have a part in discussing with the community and Eric himself the importance and implementation of features shouldn't be under-stated.
Performance - After some stress testing, I'm extremely impressed how far I can push it. It's well designed to let me push the envelope in an organized way.
Modular - Full source and a clean design lets me choose my priorities and extend as needed.
Plugins - Being able to add plug in new features as opposed to replacing parts of the engine allows you keep your game updated to the latest version of the engine without needing to manually merge them.
Extremely happy with my choice of the C4 Engine. If you serious about making a game, take a serious look at C4, you'll be happy you did!
I am updating my review. (Oct 2014)
As an engine, and programming interface, C4 is superb. It's been built and continually refined by Dr Eric Lengyel, a highly trained mathematician and computer scientist. C4's engineering is probably, and I do mean probably, the most academically sound game engine ever constructed. Sometimes I feel like I'm reading Shakespeare reading C4 code.
If your programming toolbelt is highly diverse, it will take adjusting to C4's environment. It's highly self-contained. The C++ STL isn't involved anywhere, and essentially all its components were implemented from scratch by Eric. There are clearly advantages and disadvantages with that.
As an artistic tool for translating the pictures in your head to what's onscreen easily, it's a bit of a friction generator. Every release improves this aspect some, and Terathon has expressed an increased focus to its artistic toolset / chain for the next few versions.
I have used several engines, and C4 has by far the best design I have ever seen. It's really a pleasure to work with this engine after dealing with all the hidden shortcomings of engines like Unity, and it even costs less. Plus there are frequent updates and the community is very professional.
The C4 Engine has become one of the most impressive engines out there while still maintaining a low price tag and providing updates free of charge. Not only are new features constantly being added, but the community is one of the most helpful I've ever seen.
One of the key things that makes the C4 Engine stand out is that the sole developer of the engine personally responds to all questions through the forums and provides the highest quality of support possible. Not only is he extremely knowledgeable, but he is dedicated to both the engine and it's licensees and goes out of his way to ensure that your game succeeds.