The band received some criticism for a perceived retreat to more commercial territory following the disappointing performance of "I Shall Be Released". Philip Crawley of the
Newcastle Journal suggested they had reverted "to the lowest common denominator of pop" while
Tony Barrow, writing under his pseudonym Disker in the
Liverpool Echo, said the band were "back in the usual happy-go-lucky rut". Reviewing the single in the
Daily Mirror,
Don Short characterised it as "pleasant, but not as startling as the Tremeloes can be". Geoffrey Elliot of the
Coventry Evening Telegraph criticised the song as having "none of the verve of their earlier hits" and considered its changes in tempo "more annoying than arresting". Derek Johnson for
New Musical Express described it as "typical Trems material – almost predictable. But it doesn't have such an instantly catchy chorus as some of their big hits and this could prevent it from becoming a whopper. Nevertheless, the cheerful, carefree sound, the relatively attractive tune and the bouncy beat makes it hitworthy".
Peter Jones for
Record Mirror praised the song, writing that "they are back to the optimistic, fast-paced sort of determination that registered before ["I Shall Be Released"] – and "Hello World" is the right mixture of breeziness and brashness that should restore them high in the charts". ==Charts==