Yes, there is a slight difference between "last-ditch" effort and "last gasp." "Last-ditch" is used to describe a final effort or attempt that is made in a desperate situation when all other options have failed. It implies a sense of urgency and the need to take extreme measures to achieve a desired outcome. This phrase is used more frequently than "last gasp" and is often used in a serious or dramatic context. "Last gasp," on the other hand, refers to a final moment or action that is taken just before the end of something, such as a game or a project. It implies a sense of finality and the idea that there is nothing more that can be done. This phrase is used less frequently than "last-ditch" and is often used in a more lighthearted or metaphorical context. In terms of nuances, "last-ditch" suggests that the situation is dire and that the outcome is uncertain, while "last gasp" suggests that the end is near and that there is little hope of success.