I'm sorry, but a game, which fails to establish the basic environmental instructions can't be simply dismissed as "oh that's okay". When I download and try a game, I invest time. It is my choice to play the game, that's true, but it is also an obligation from a developer's side to properly market/publish the game. You can't just feel like I was wrong, just because you think I was "harsh". I've played thousands of game jam projects and I've been involved with game jams too. Failure to establish the guidance for a player is a major flaw. And we are talking about masses of people, who don't even care about if the game is made in 7 or 5 days, those people just want to play the game and judging from their perspective, again, just simple add 1 line of text, all this can be avoided.
And you know what, if the developer/developers cared about the project they would actually respond first and be more open to the issue. The lack of any response proves my objective point even further, that they didn't really focus about the main "gameplay" aspect of the game. Sadly, they don't even care.
FYI the pointers from the start of the game didn't help at all. I don't know what version have you played, but main had nothing of sorts and I had to figure things out for almost 15 minutes.