、。
In the continuous excitement, the 30-minute showtime passed in what felt like no time at all.
Literal
Excitement [genitive-の] continuous [to-に], in-the-blink-of-an-eye [without-もなく] 30-minute [genitive-の] showtime [subject-が] ended-up-passing.
A post-event reflection. 興奮の連続 ('continuous excitement,' 'a string of thrilling moments') is a noun phrase that sets the tone. あっというまもなく is a compact variant of あっという間もなく — literally 'without even the time to say あっ' — meaning 'in no time at all,' 'faster than you could say Ah.' The more common form is あっという間に ('in the blink of an eye'), but without the も. ~てしまいました ('ended up X-ing') marks the passing of time as faster than desired, with a note of regret that it couldn't last longer. ショウタイム (showtime) is a loanword.