Was going through puzzles I saved an never finished. Managed to get a lucky guess on this puzzle. As Biglib007 said, all the squares are connected.
**SPOILERS** The entire middle spiral can be solved logically, so my hints are focused on the outer squares. The hints will also help solve the middle spiral though. R1 C14 ; R2 C13,18 ; R4 C4,23 ; R5 C3,24 ; R10 C1,25 R13 C1,24 ; R15 C2,23 ; R20 C1,4,23 ; R25 C10,23.
**SPOILERS**
The entire middle spiral can be solved logically, so my hints are focused on the outer squares. The hints will also help solve the middle spiral though.
R1 C14 ; R2 C13,18 ; R4 C4,23 ; R5 C3,24 ; R10 C1,25
R13 C1,24 ; R15 C2,23 ; R20 C1,4,23 ; R25 C10,23.