Originally Posted by ILoveAztecChick
What do you mean by situation specific? In the Wily 2 area where you're supposed to jump through a phantom block I actually used two concrete shots because I fucked up the first time. I got the achievement on that run though. I was thinking maybe it's because I used spike guards to get across the section in Wily 1 where you're supposed to use Rush Jet, so it made up for my mistake.
It's hard to describe. I'll put it this way, if you save 10 concrete shots by not using them on Wily 4, you can't use that same amount or even less somewhere else - it will void the achievement. This happened to me on Wily stage 2 where I died and had to re-use the laser trident to destroy a block underwater. It voided my achievement and I had to play again.
However, on the same part you are talking about with the phantom blocks, I screwed up a rush coil, and re-used it. I made it the second time, and I got the achievement on that play through. So, it may just be that you can't die and re-use something. The laser trident voided the achievement, the rush coil did not. this may also mean that Rush energy does not count as weapon energy, but I am not sure.