For those of you (as well as me) who prefer having bomber timers, no directional selection, and such, I have been thinking of adding a difficulty selection that toggles these behaviors: an "Original" mode that enables bomber timers and disables directional selection, skill assignment while paused, frame-stepping, rewinding (if it's ever implemented), builder/digger/bomber guides (ditto), and maybe resuming from replays; and another mode (which I haven't named yet; perhaps "Normal" or "Easy") that behaves like how SuperLemmini currently does. I think the latter mode will be the default unless you guys prefer the "Original" mode.
P.S. Whilst there are a few SL peeps active on here at the mo, does anyone know what this button does?
As others have determined, yes, that button disables vertical scrolling. I implemented it because Lemmings 2 also has that control (albeit only on the keyboard; it's the S key). If it would reduce confusion, I can remove that button for levels that don't feature vertical scrolling (which is almost all levels).
Also it would be nice if you added ohaya lemming san level from the SNES Version since you have some other levels already there from like the amiga set and dos' vacation in gemland.
I'll add it and the Sunsoft levels if I can extract them directly from the ROM. (I managed to do it with the Genesis version but not the SNES version. I think the SNES version's levels are compressed.)
(And yes, I will eventually include the Genesis levels with SuperLemmini rather than provide them as a separate download.)