hello Christina,
Scheme+ is an extension syntax to Scheme. It goes in the opposite direction of Wisp or Rhombus (based on Racket) by keeping the same number of parenthesis, but they are just differents : ( ), { }, [ ] and it allow the use of infix expressions. It is my idea, i think Scheme musk keep a strong identity with parenthesis.
Parenthesis have advantage on indentation (and inconvenient i admit). For example if you comment a single line of indented code (python for example) that was used to define a loop you have to reindent all the body code in the loop. If you want to move a block of indented code you then have to re-indent it specifically for the new place too.
Anyway scheme and scheme+ ,C ,C++ code are still indented for readness even if parentheses would be enough to validate the syntax.
Regards,
Damien