All 42,645 bytes of the game block are accounted for, the modules reassemble byte for byte and the rebuilt tape has the same sha256. What is left open is little, and it goes here.
At the end of the data, behind the last block of compressed graphics, there is a 45-byte loader nothing runs. It jumps to 0xC000 like the real game, but it leaves a different memory map: ROM in pages 0 and 1 and RAM only in the top two, so in that version the data lived under the BASIC ROM rather than under the BIOS. It also uses variable 0xA87D, which does not exist in this version: the game block ends at 0xA694.
So it is a leftover of another build of Ale Hop!. Which one it was, and whether it ever came out, is not known. The details are in the dead bytes.
In the title-screen piece, between the ret at 0x88D9 —which hands control back to the loader— and the image's pattern table, which starts at 0x891C, there are 66 bytes left. The listing gives them as leftover that never runs, and marks that as a guess: what they were has not been worked out.