I’ve gathered some information on both the topic of ‘why Unity’ and ‘optimization’ from this games Discord server;
Why EHG chose Unity
“Unity is the best engine for rapid prototyping, and lets you have very granular control within the engine through code; two things that are very important to us as a team, and have allowed us to iterate as rapidly as we have.” -Mitchell (posted March 31, 2018)
“The team was at least somewhat familiar with Unity when we started. Versus Unreal, they both have similar capabilities now but Unity has a larger install base and therefore has more plugins and assets developed for it. A custom engine has the potential to be the most performant but it would take much longer for us to develop as it’s a whole separate layer of logic. I’m not a programmer, but that’s my read on it.” -Hackalöken (posted December 20, 2018)
“That’s basically the shape of it. I was one of the primary advocates for going with Unity because it’s the engine I had the most experience developing in and I knew how flexible it is. Unreal is also a solid engine, but (as far as I know) we didn’t have anyone with much experience with it, so going with Unity got us started sooner. Like Hacka said, developing a custom engine is very time consuming, and had we gone for that route it would have taken us much longer to even start testing, which for a first time indie team was a big deal. Going forward it also would have meant we would have to devote resources to developing and improving our engine, and onboarding new team members would be slower (many people have worked with Unity, nobody else would have worked in our custom engine)” -Mitchell (posted December 20, 2018)
“We looked at multiple game engines, and Unity was the best for our team. This was due to a combination of our internal priorities (e.g. pace of development), the experience of various members of our team, and so on.” -Sarno (posted July 16, 2019)
Optimization
"One of the strengths of Unity is that it facilitates rapid development and prototyping, which to-date has been the focus of our team. Naturally, this has come at a cost in terms of both performance and graphics - and we have occasionally performed passes on both. …and closer to release we’ll be switching gears to focus on graphics, optimization, and polish.
As I’m sure you’ll be aware if you’ve worked with Unity and / or other engines, it is very costly (in terms of man-hours) to optimize a game, and you never want to risk wasting time on optimizing art assets, shaders, or combat calculations that end up not being in the game at release. This is why game development is a notoriously iterative process, and why the majority of studios initially focus on concepting and fleshing out a game before shifting over to improving graphics and performance." -Sarno (posted May 3, 2020)
So, in short, the team had the most experience with Unity and it allowed them to quickly develop and test things faster than other off-the-shelf game engine suites. Also, while a custom engine would perform far better it would also cost a lot of money and require resources the team didn’t have. Lastly, the game is still being optimized and each patch brings some form of optimization but the bulk of this occurs later in development.
As a small indie team I think everyone can agree that they made the right choice to ensure this game would actually finish development. As Sarno most eloquently put it, “We’re an indie team, and all of EHG’s shareholders are members of our team. We’re just a bunch of nerds trying to make a video game.”
