Thanks for playing, glad you enjoyed it! While playtesting we realized that infecting every last human was very annoying, since they tend to hide away, so we adjusted it so you only need to infect 90% of them which is why there were some humans left, the 23/22 is just some weird integer division thing when calculating the amount needed to win.
We wanted a higher number of people per level but godots skeleton animation seems to be horribly optimized which led to extremely bad performance with more people. We didnt want the game to be too hard for people playing it so thats why its pretty easy (we were gonna add a harder difficulty but ran out of time :( ). Regarding the tutorial, yeah its not perfect, but as I said we ran out of time unfortunately. Sorry you had a hard time with the upgrade system, we had the same problem with spamclicking by mistake when leveling up when playtesting 😅. Thanks for playing!
Thanks for playing it! There were some post-it notes around the train that were supposed to teach you how to operate it, sorry if it wasn't clear enough.
