A key objective in DNA-based material science is understanding and precisely controlling the mechanical properties of DNA hydrogels. We perform microrheology measurements using diffusing wave spectroscopy (DWS) to investigate the viscoelastic behavior of a hydrogel made of Y-shaped DNA nanostars over a wide range of frequencies and temperatures. Results show a clear liquid to equilibrium-gel transition as the temperature cycles up and down across the melting-temperature region for which the Y-DNA bind to each other. Our measurements reveal a crossover between the elastic G'(ω) and loss modulus G"(ω) around the melting temperature Tm of the DNA building blocks, which coincides with the systems percolation transition. This transition can be easily shifted in temperature by changing the DNA-bond length between the Y-shapes. Employing also bulk rheology, we further demonstrate that by reducing the flexibility between the Y-shaped DNA bonds we can go from a semi-flexible transient network to a more energy-driven hydrogel with higher elasticity while keeping the microstructure the same. This level of control in mechanical properties will facilitate the design of more sensitive molecular sensing tools and controlled release systems.