Long time user, first time reviewer. A friend showed me this game, and so far, I have yet to stop playing. It's quite addicting!
There are, however, a few details that I think should be included. During gameplay, I would like a short description on the side or something to remind me what rules are implemented at the time.
Additionally, and I'm sure I'm not the only one, but I'm a bit dyslexic when it comes to mixing colors. I would like to see, along side of the description I mentioned earlier, to see a color mixing chart, like having 2 colors like "blue" + "yellow" = "green". I always end up intentionally colliding the trains just to see what color they make, then I forget again and have to do it again, and again.
If anything, these could be preferences you can set in a settings or preferences menu.
Overall, this is an extremely addicting game for me :)