if that window were just a few inches to the right or the sump pit a little to the left.
Option 1) Move either the window or the sump pit. That's messy, expensive and time consuming.
option 2) put in a smaller window - Still have siding and such outside to deal with.
option 3) angle the wall as suggested - yeah, will look weird.
option 4) step the wall like this
- The stepped wall would look better than an angled wall. It would also create a little nook for shelves for books, videos or chackas.
Option 5 - build wall past the window and have the space unfinished storage.
Personally - I would opt for moving the sump pit.
FYI - We did a series of podcasts where we talked about basement finishing, check them out if you want at Basement Finishing Series