After the Dreamcast, the series' critical standing began to decline. Evans-Thirlwell summarized further 3D "Sonic" games as "20-odd years of slowly accumulating bullshit". Although reviews for "Sonic Heroes" were mostly favorable, Stewart said this was when the focus on story and cutscenes became unbearable. The decline continued with "Shadow the Hedgehog", widely criticized as a misguided attempt to bring a sense of maturity to the franchise, and reached its climax with the critically panned "Sonic '06". "Sonic Mania" developer Christian Whitehead said that the changes to the "Sonic" formula "stemmed from a – perhaps misplaced – desire to continue to push Sonic as a AAA brand". Journalists, Whitehead, and former Sega of America marketing director Al Nilsen criticized the number of characters added to the series, although Naka had previously justified the additions as necessary to please fans. Evans-Thirlwell argued that Sonic Team had never successfully translated the momentum-based gameplay of the Genesis games to 3D, and that unlike Mario, "Sonic" never had a 3D "transcendental hit". Simon Parkin of "The Guardian" noted that whereas Mario creator Shigeru Miyamoto reviews every "Mario" game prior to release, the individuals who shaped "Sonic" (Naka, Ohshima, and Cerny) left Sega.