Similarly, there was no state-of-the-art coding in this game:
* http://www.thewayoftheninja.org/n.html
They had plenty of technical challenges pushing the performance of ActionScript in browsers at the time in order to keep the game moving smoothly.
Most of the "real" updates to minecraft are in regards to enemies, item recipes, "biomes" (which presumably don't change the generation logic much, just the spawn rates), etc.
Roguelikes I imagine are also in the same vein; it's all just fiddling with the numbers, for balance and "fun"
Simulation focused games on the hand are probably a better candidate for "purely programming" programs, but even then, the complex stuff is probably in the vein of emergent behavior; something you don't at all strive for in normal programming. And they still presumably make a large chunk of their decisions based on "fun" instead of reality. The harder you strive for reality, the less a game it becomes... Maybe Grand Strategies then; they pretend to simulate a pre-generated complex environment, but avoid emergent behavior for the most part.
Really the only thing I could safely call a "pure programming" problem is a tech demo that happens to be a video game, ie Carmack's stuff. But even then...
I think it might just boil down to that very few video games are both good, and disinterested in player enjoyment. The key distinguishing feature of video games as a media is human interaction; it's difficult to imagine a good game where this is not the predominant motivator. Even Dwarf Fortress keeps it in mind pretty strongly.
Also, don't forget to hire a sweatshop full of eager kids fresh out of high school or junior college and make them work 60-80 (or more) hour weeks for peanuts to hit those Christmas deadlines. They probably know more about the ins and outs of the third-party middleware you licensed than you do, since it's literally all they do, morning, noon, and night. Granted, this bit may be difficult on a $85,000 budget -- if you plan on hiring developers from the first world, that is. You could probably hire a team twenty strong from China or the Ukraine for less than half that money and keep them busy for a year. After which you'll have a beta with a few bugs, some of them showstoppers, but still good enough to ship as the final game while you ready a day-one patch.
I mean if we're going to regurgitate "industry best practice" into this thread, why not go whole hog?
If you are getting into the indie scene hoping to have a million seller, then unless you are a rare genius (e.g., Notch) your $85,000 is better spent on Powerball tickets. Do it for love of the craft, whether you use your own or a licensed engine. And for God's sake start small.
I think, in this case, the author meant he didn't use one of the big commercial engines. Aside from all that, I also agree that it's not a really big mistake.
It is possible the knowledge he gained from writing his own engine, will allow him to get a better paid job down the road for example. But most likely those $85 000 would be better spent on education.
That is, of course, assuming that you think sales are THE thing that matters in indie game development. In which case you are probably better off attaching yourself to a large studio such as EA, than going indie.
1. Writing his own engine: This is an often discussed issue, but basically it boils down to 95% wasted resources. It's all time you should have been spending on a unique angle for your game, or a specific game-making gameplay feature etc.
2. Trying to create an RPG, JRPG or MMO: As a solo person these are highly problematic. The amount of roles you need to cover for these genres is ridiculous by yourself, which brings us to him outsourcing jobs because of the large art requirement.
3a. Spending $85k (Project 1) / $15k (Project 2): There was always only a very small chance to get $85k back except by going viral (such as with the Stardew/Undertale comment), which is in itself a very small fractional percentage chance. Aim for something reasonable such as $1k expenses for a first project. $10k is already too much and few projects will make that back. Spending more on project 2 than you made on project 1 is also an issue. Cut back as much as you can.
3b. Spending $4k on PAX (essentially advertising): As he himself discusses, he had no way to gauge the impact of going, but again it comes back to it being a really big $ amount for a first time indie developer.
4. Niche games are hit or miss out of the gate: Astral Traveler is the type of (Runner) game that doesn't promote word of mouth. They for example need some angle such as being extremely hard, pretty, controversial or competitive that will encourage people that they themselves need to give it a go, or watch someone else give it a playthrough. It comes back to asking what is the hook for the game?
5. Tech Support (His new/3rd Project): Gauging whether something will be a success is very very hard. At the very least he seems to have scaled down the costs, but on the other hand it doesn't look like an extremely interesting game at the moment. A big problem for indies is to find the correct scale of game. Too small and you're seen as a throwaway cash grab, too big and as an unknown that's not pushing the frontiers of the art you'll never make your money back.