The tone is nostalgic and melancholy. The speaker remembers a simpler and perhaps more peaceful time before European colonization in Australia. The boomerang and woomera were Aboriginal weapons: artifacts associated with this previous period in Australia's history. The speaker affectionately recalls this time before European colonialization and industrialization. This was a time when people were freer, more in touch with nature and, according to the speaker, happier.
This is a common theme in Romantic poetry. The nostalgia is for a pre-industrial or pre-civilized time when people were concerned with the simplicity of live: not so concerned with the rapid pace of historical progress. This historical nostalgia is analogous to the personal nostalgia for the simplicity and wonder of childhood. This is also a theme common to many Romantic poems. So, this poem is nostalgic and melancholy.
But its tone is also resentful because it is a lament about the European colonization of Australia. Noonuccal was an Australian poet and activist for Aboriginal rights.