Yeah 2.1 is the core, but there's always an updated exe you can run (It's small and doesn't need to be installed, so it's easy to manage).
Currently the newest version is 2.44 but theres some issues with it, so I recomend using 2.43.1L (It's no longer on the wiki, but you can find it in the forum, or just ask for it, I would upload it here, but the topic we're in doesn't allow it.)
Also take a look at all the new bots, you can find them in the Starting gate or in the league files.
And if you want to learn more about coding bots and feel like being challenged then check out the leagues (I recomend starting with the F3 league).
Also it's hard to make out what evo bots are doing at times... sometimes near impossible.
For this bot it looks like it was set up to evolve in several different directions and eventualy started pushing something into .tie
Also there's a good tutorial on the Wiki on how to build a bot, or you could just start off looking at the bots in the F3 league starting from the bottom and working your way up. (This way you can also see what kind of difference a single added gene can make). The F3 league doesn't allow the use of ties, shell or any of the fancy stuff... only movement, shooting (only -1 and -6 shots) and boosting shots. No poison, venom, shell, slime, ties, memmory shots, viruses, raping or anything of that kind, you can read the specifics in the F3 league discussion in the forum (In the bot tavern).
There's also the F1 league with no rules and the F2 league with a few rules, but these are both harder to compete in.
And welcome