Well, you definitely made me laugh! (At the humourous sign text, not at your level-design skills.) Especially the "cheesy toasts of death... nom..." one.
Categorisation-wise, I'd call this an environmental... possibly the smallest environmental ever.
There is a wall-swim-inducing void directly above the start screen, which I wound up in after climbing that wall above the (mmm...) toasts. This can be corrected by placing the No-Climb object (Bank 0, Obj 11) on an object layer (4-7) over the wall tiles -- like you did on the third screen, actually, now that I've looked in the editor, but I'll leave the explanation in for the benefit of others -- though double-jumping will still allow a glimpse of the void, so you might want to either take away one of the jump powerups, or just give that top screen a sky background instead of the void background.
I didn't come across any instances of a tile being background in the sense that Juni can walk
in front of it because it's on layer 0, 1 or 2, and then in another screen Juni can walk
on it because it's on layer 3 -- which is what people mean when talking about the foreground/background issue. Having scenery tiles in the part of the foreground that's apparently closer to the player than Juni, and the same scenery tiles in the 'distance' of the background behind Juni, is fine.
I'm afraid you may be slow, however: You get to use two tilesets per screen, not one. (Don't feel too bad for missing that; it took me forever to realise that the music and ambiance setting were right in the main edit window, not in a 3rd-party screen or requiring direct editing of the world.ini file... "if it had been a snake it would have bit me" definitely applies.)
Just above where the tileset graphics are displayed in the editor, there are three numbers: [
BG] XXX [
TILEASET] XXX [
TILEBSET] XXX ...you've already figured out that clicking on the number next to BG changes the background, and clicking on the number next to TILESET A changes that tileset. To see what's in tileset B, you have to click [
TILEBSET] XXX (the text 'tileset B' will then turn that same amber-yellow, to indicate it's active, that shows you which layer is active in the 1-7 layers listing). Voila! You can now choose and use a second tileset.
(Speaking of backgrounds, by the way, I was surprised to realise you didn't use one of the backgrounds that already has stars on it; putting all those stars in on a blank dark background allowed for the interesting effect of the overall number of stars in the sky decreasing as the red stars increased, but it must have been tedious putting them all in...)
The 'death' objects you placed over the water on the final screen were unnecessary, by the way, as the water-surface tiles are already deadly to the touch... or did you want the effect of the death coming just before Juni actually touched the water, for some reason?
If you meant for the music to continue playing on the second and/or third screens, the same music number has to be set there. Otherwise it just fades out. Also, when you place signs, it's usually better to use just one SIGN object (Bank 0, Obj 17-19) and, for other squares you want the sign text to be visible in when Juni moves, use the SIGN AREA objects (Bank 0, Obj 29-31) instead. That way the text box doesn't move when Juni does.
One last tiny little thing... there's a typo in Sign C on the start screen. It should be "its beautiful stars", not "it's beautiful stars"; "it's" always means "it is" whereas "its" is, like "his" and "hers", a pronoun and thus doesn't need an apostrophe to show possession the way "Juni's" or "people's" would.
Incidentally, this is the kind of level people don't usually release (or upload to the archive if they do make it available) because it's more of a "getting practice using the editor" level. I think it's a good thing for people to get feedback at this stage, myself, but other forumites will probably disagree in not-necessarily-polite terms.
On that note, however:
http://www.knyttlevels.com/levels/the%20Iza%20-%20the%20Iza%27s%20first%20level.knytt.bin -- or, to get fancy,
click here to download the Iza's first level <-- here is the download link for your level, formatted two different ways. Here's how I did the first one:
[url]http://www.knyttlevels.com/levels/the%20Iza%20-%20the%20Iza%27s%20first%20level.knytt.bin[/url] and here's how I did the second, fancier hyperlink-text one:
[url=http://www.knyttlevels.com/levels/the%20Iza%20-%20the%20Iza%27s%20first%20level.knytt.bin]click here to download the Iza's first level[/url]ETA Curses! Miss Paula is superiour to me in all ways, especially speed of posting...