MONKEY BUSINESS was reputedly the very first commercial game ever released for the Amiga. It was reportedly published in late 1985 by little-known U.S. software company The Other Valley Software.
Whilst some gaming icons and many Amiga enthusiasts alike popularly believe(d) that MIND WALKER - coded by Bill Williams and released by Commodore in early 1986 - was the first commercial Amiga game ever published, at least one or two pioneers involved in the Amiga's infancy assert otherwise.
Based on anecdotal evidence currently available, MONKEY BUSINESS (a low budget Donkey Kong clone released for the A1000 by The Other Valley Software in late 1985 on mail-order and, subsequently, sold in U.S. computer stores) - in all probability - was the first commercial game ever published for the Amiga.
Indeed, MONKEY BUSINESS was reportedly released soon after the Amiga 1000 began shipping in the U.S. in September 1985, and has been confirmed as the first game to have been received for review by the world's first Amiga print magazine, Amiga World, when it was established in 1985 (see review HERE).
'My candidate [for most obscure Amiga game] is Monkey Business from The Other Valley Software.
It's a Donkey Kong clone released in late 1985--the first game Amiga World received (I was AW's games editor) and, quite possibly, the first Amiga game, period.'
[Source: Peter Olafson (ex-Amiga World games editor), "The Most Obscure Amiga Game" online thread (23-Feb-2000); comp.sys.amiga.games newsgroup]
'Over the years, Mind Walker has acquired a beard of myths that have gained credence through repetition. Like most myths, they contain a grain of truth. But only a small grain.
Mind Walker was not the first commercial Amiga game. Although among the earliest Amiga games - and probably the best distributed of them (owing to CBM's participation) - Mind Walker wasn't actually released until early 1986, when the Amiga had already been available for some months. The earliest commercial Amiga games I've been able to find are Monkey Business and Delta Patrol - both from The Other Valley Software and released in late 1985.'
[Source: Peter Olafson (Amiga games journalist), "A Tribute to the Work of Bill Williams: Part 1"; Amazing Computing, Vol. 13 Issue 2 (Feb 98), p46]
 Until more recently, no disk image of MONKEY BUSINESS - that is, neither a scene release or an original version of the game from the publisher - was readily accessible on the internet or from any other source.
In October 2018, however, a scene release of MONKEY BUSINESS was made available to the Amiga community after resident EAB cracker Ross managed to magically rework a bad disk image released by an obscure European cracking crew and located by dlfrsilver (see HERE, specifically post #20 onwards).
 Additionally, photos of the original MONKEY BUSINESS game box & disk exist and are available for viewing HERE (see Miscshot).