Personally I think the difficulty is great as is, but there is a bit of a curve to figuring out how to manage enemies effectively. If we get more levels, then yes, definitely lower the difficulty of the first one, but I think that telegraphing enemies a bit more and making the game more forgiving as you learn should take out any frustration players have.
Edit: I think one of the potential issues with difficulty is that you are heavily incentivized to play very slow and cautious due to input speed. I suspect that some of the players having a difficult time with this are trying to play reactively, which is near impossible due to slow startup on inputs.