From reading the OpenRCT2 code base it was C-style with PUSHA features. You basically need to create a bunch of wrappers over function calls, to construct a sort of domain specific language/macro collection for your specific application.
I can respect the dude but in many ways RCT was a continuation of his previous games.
As people who study software development we have to sometimes call it like it is.
Using ASM was not the right choice as it didn't provide any obvious advantages compared to languages like C.
The genius of OpenRCT2 wasn't in the language choice but rather in the immersive world available in your cereal box.
There is no right language choice for a game, same how there's no right choice to live a life. There are advantages and disadvantages, and in retrospect, we can see how things turn out.
There are language choices in projects where the choice seems to hurt the project, that's for sure. Wrt/ RCT, I don't see a single downside though. The cases I'm thinking about are Minecraft, for example, with its horribly performing Java code. Cities Skylines with their engine choice and usage, resulting in 30-40 fps even on high end hardware. Project Zomboid with LUA - many performance problems, and artificial limitations to keep performance to a reasonable limit.
Also consider that often, a project either gets off the ground with the sub-optimal choices, or it doesn't, at all. And as we see from the results, a sub-optimal, but fun game is better than an optimal, but non-existing game. At least if you consider fun and success desirable.
It was the right choice for the developer because he had years of experience developing other games, he probably had a structure and a good enough library by the time he started working on RCT.
I can respect the dude but in many ways RCT was a continuation of his previous games.
As people who study software development we have to sometimes call it like it is.
Using ASM was not the right choice as it didn't provide any obvious advantages compared to languages like C.
The genius of OpenRCT2 wasn't in the language choice but rather in the immersive world available in your cereal box.