Preview in The Games Machine (italian) March 1992 [page 12].
(Right page of preview see Snow Bros.)
No manuals found.
On level 1: go to the left rather than the right, pick up the 3 bonus lives and continue left until you are up against the edge/wall. You will now have infinite lives and can use the function keys F2-F7 to skip levels to the corresponding level (e.g. press F3 to skip to level 3, press F5 to skip to level 5 etc. etc.). The level skip only works from the first level. You will need to at least press F2 as you won't be able to complete level 1.
[Source: Abaddon, via message posted on EAB]