I was on my third Mass Effect playthrough before I realised the Mako cannon thing.
It also took me until my second Mass Effect 3 playthrough (and reading a GameFAQs post) that I realised you could re-map the "Y" power.
It also took me until my second Mass Effect 3 playthrough (and reading a GameFAQs post) that I realised you could re-map the "Y" power.