"Das me" Dat's (…no good way to write that, is there?)
"Something cool here later"…okay.
You have the Super Mario World noteblock problem with your red breakable springblock: if you hold run and a direction you won't spring up, you'll just bounce each in turn (destroying them and not going up). Running left at the last segment of 2-1 will do this. [acc: fast, speed: slow]
Boulders instant kill? Well, that's one way to prevent skipping past them. It's not friendly, though.
The push-one-space blocks' instant move doesn't look good. 2-2's three-tall stack-to-push can also be skipped by not pushing any and run-jumping from the top of its initial position.
Ice block [or hamburger] may skip the final segment of 2-2; this seems intentional given the provided platform access.
The cannons that just drip fry-bombs look odd, since they just drop straight down. (or was Ronald stuck in a cannon? not sure)
2-4 the second switch (enables a floor to run over a gap) may be skipped with runspeed fast. Or burger.
in fact, you can phase through the top brick on the screen in 2-4 by jumping and down-B burgering.
You can get in the ceiling with burger down-B. if you have an upper corner you're facing away from. you gradually come out, though; I was unable to actually get stuck. (Burger also lets you bypass pushing that block all the way, but I expect that's intended.) In fact, burger lets you get through 100% of the item placement puzzles in this level, without placing any, if you're good. (Not something you should change, imo.)
…however, that you can just jump over the item-placement section with a jump, down-b, jump is maybe bad?
Placed items vary in resulting palette.
exiting the shop puts you on the latest world, rather than where you were.
Dying after buying something means you don't have it? huh.[a: no, your inventory override for 2-5 is why I couldn't. The ice block I bought is back at 2-6]
Being unable to see where Nova is when placing blocks is a handicap when you're trying to place from midair+inventory.
Dropping onto screen 1 of 2-5 can have the sunmask get a cheap hit. In general such screen transitions that aren't ladder-based can yield a cheap hit.
2-5 killed me a lot until I started using the items. Nice secret cache.
2-6: Chips, and suction boots to defeat conveyors? (oh, and green-button alternator blocks?) Very obviously taking from Chip's Challenge. (except suction boots don't make much sense for defeating mid-air force-direction-thingies.)
Did you forget to implement the actual counter for chips remaining? There's a chip by the HUD but no number. (or is that "regular inventory is disallowed"? guess it's the latter.)
Tornadoes don't quite have a consistent carry spot for Nova; was bounced up and down while in one.
Attack-while-climbing lacks animation. Or facing indication other than attack.
2-7: placed items still don't affect the palette of a square. This means that the placed up-arrows (which aren't hinted to be forcibly-inventoried) don't look red as an arrow that WILL go off when headbonked(/touched) should.
Standing up against the side of a boulder as it begins to fall = death
Standing precisely between two pass-through platform squares still means you can't pass down through either.
Ah, finally see the point of the dithered blocks: boulders can't pass through.
2-7's second-to-last enemy placement, with two tracking monkeyfires and two remote bomb turrets, is a bit nasty…frankly, easiest to just tank a hit there.
uh, whatb oss?
known, I guess.
Ice power doesn't have the burger 1/j limit. It's not really possible to abuse this, though. Also, it won't freeze all of a surface if you slide it off the edge normally, only 3 on, 1 off.
I managed to defeat one of your "don't go over the level" bits in world 2,
can't remember which,
by …going over it. (2-1's first, using an iceblock or burger, and jumping)
Running over the roof at start of 3-1 doesn't hit the money-and-checkpoint platform. Also, you can access this roofrun from that platform or the very beginning.
I managed to beat 3-3 without riding on any minecarts (except to move them out of the way). I suspect I'm not on the usual difficulty curve.
It was fun and challenging the first time.
Occasionally checkpoints wouldn't count. I couldn't figure why.
Pressing start in the options menu, even if you reach it by pausing, sends you out to level select. This is bad, if you were expecting to unpause and resume.
edit to add: no guard against using a block on Nova's location, and it only takes one to trap yourself…but there is always that "restart from checkpoint" menu option.
edit to add 2: winning 2-8 fight in mid-air put me in a place I instantly fell to my death, rather than the exit location.
eta3: discovered a roundabout infinite jump. Down-B iceblock, jump, pause, select ice block (using one up), repeat.