This is an interesting discussion and worth having with some careful thought and introspection. My own perspective will be largely driven from the Simutrans-Experimental side of things, but that is worth considering, too. There are a greater number of competing games now than there were years ago (the mid-2010s seems to be the heyday of the independent game), and, interestingly, many of those are "retro" games that emulate games from the 1990s - the very era that Simutrans is actually from. The age of the game itself ought not to be a reason for it to become less popular, especially if it is continuously developed and enhanced, although the additional competition might be.
There is to an extent an important feedback loop: the more popular that Simutrans is, the more people who will play it, a small fraction of whom might go onto help with development and/or publicity, thus improving the game or its advertising, making it yet more popular (and more enjoyable for those who already play it).
Simutrans could probably do with more social media presence as Prissi indicates; the forums are useful for discussion between established community members, recording information and welcoming and helping new people, but they do not fulfil the same sort of functions as social media. There is a Simutrans 'blog and Facebook group, but I do not think that either are very active. (And this returns to the feedback issue, as the inactivity may well be due in part to the lack of people available to do this).
Youtube is another relevant outlet in two ways: firstly, it can be a useful means of advertising Simutrans (there is already an independent Youtuber who has Simutrans content: look at Shining Sword Gaming; Youtube is a very popular outlet for gaming at present) and it can also be a good way of providing tutorials. Tutorials are important to allow players to learn about the game more quickly and easily and with less frustration. Youtube tutorials are probably easier to produce than in-game tutorials. I have started using Youtube for tutorials for Simutrans-Experimental, and this seems to be quite popular.
Turning to the more substantive considerations (and focussing on Simutrans-Expermiental, since that is what I know the most), the aim is for Simutrans-Experimental to find a very specific niche not occupied, so far as I know, by any other transport game, which is of a transport simulation that is highly realistic (both economically and operationally), that can be played in semi-persistent large online games (perhaps being reset after a year or so, depending on the in-game timeline) with a multitude of other players with interesting and realistic emergent game-play. In particular, I am keen for the game to have both great depth and great breadth, a feat not possible with more modern game engines that use 3d graphics (which take far longer to produce, reducing the number of graphics that can be produced) and fully agent-based simulations (which take far too much CPU time to allow for massive maps that also have lots of local detail). I want players to be able to enjoy setting up a detailed pattern of local 'bus routes in a town and a realistic network of airline routes (which I hope will be much more interesting when I eventually introduce a portals feature allowing very long-distance overseas transport without increasing the map size) which interact with each other in realistic and interesting ways in the same map. I do not believe that any game in existence or that is known to be being planned does anything like this.
This is why I am concentrating on fixing problems in multi-player gaming, spent a long time last year implementing multi-threading (so as to allow for good performance on very large maps), and am focussing on the things that will allow me at last to undertake a comprehensive exercise of economic balancing. It is unfortunate that the development is taking such a long time, but that is the result of there being few other people helping with coding at the present time and me being a self-taught amateur in that respect.
However, what I do plan to do in the near-term is adopt a modern practice in respect of Simutrans-Experimental: to switch to an early access model of development. I had planned to drop the "Experimental" name and replace it with "Extended" some time ago, but have not been able to do so yet, since what is still officially the current release version is still named internally "Simutrans-Experimental".
The plan is to deprecate those old releases from 2013, and instead focus on nightly automated builds, where players can download the latest development version of what will be "Simutrans-Extended" (the new name avoiding confusion). The current state of the computer game industry shows that players are often happy to play an incomplete version of a game that is under active development under the "early access" model. In fact, these builds will probably be more stable and better balanced than the old release builds on the 11.x branch from 2013 because of the amount of development work that has gone into them since then.
Finally making the new name official will allow me to set up social media accounts in which I can post short messages about the latest development work regularly, and will also make it easier for me to refer to the name in the Youtube videos. These videos can have the dual purpose of being advertisements for Simutrans-Extended as it will be and tutorials for existing players, by using the distinctive style of the old British Transport Films from the 1950s/1960s which were themselves often either detailed instructions for transport personnel, as in Single Line Working
, more artistic endeavours showcasing transport infrastructure, such as Terminus
, or documentaries educating the public about transport, such as Inland Waterways
. I am also considering making a tutorial video about how to make new objects for the pakset, which might make people interested in creating things to improve the pakset.
This is why I am so particularly keen to get cross-compiling
to work: any assistance that anyone can give with this would be much appreciated.