I was not expecting what I got myself into when I started the game. I'd say I was positively surprised. Let's go over some things about this Game together:
Summary
Adherence To Theme
You play as a Warehouse-worker who accidentally got trapped at the end of closure and has to figure out a way to escape! the Theme was both incorporated in Gameplay and Story, Excellent!
Game Design
- When playing the Game I noted a couple of things that would bother me. For starters, the highly important Boxes can be stuck indefinitely in every corner and it is very easy to get stuck in every Level. The most probable solution to this would be a pull mechanic, possibly by press of a Button. That is how the old school "Tomb Raider" games did it. The other way one could go about this is to adjust for it in Level Design, which could lead to either weird looking levels or too obvious solutions for the "puzzles".
- The Jumping was neat, the Physics where outstanding, collision detection worked as intended for the most part.
- You already know, but I need to point out that the "trampoline" jump is coded perfectly and is working fully as intended. Kappa ;P
- The intro cutscene was a pleasant surprise in terms of Storytelling. If I am entirely honest though, the ominous harsh closing sound of the gate had me expecting something more grim, like (again with the PSX classics...) "Oddworld" haha. Possible ideas for some alternative level design to be had, in case you want to make a grim level.(Since it also gave me some "Limbo" vibes.
Originality
A neat idea for a puzzle platformer. Nothing offensive or daring about it, that's why I couldn't give full points here. I can't quite put my finger on it, something is missing. Maybe if the game went more into a wacky, comedic side, it would've given me more Portal feels. Like some gameplay objects inside the boxes had the potential to be even more outlandish than a trampoline.
Oooor the game went the aforementioned "dark" route and made the factory at night a place with horror or creepy influences. At any rate, for your game, since you are indie Devs, you have the power to create something super unique without worrying too much. There is a reason why corporations did not create "Hollow" or "Shovel-Knight", "Limbo", "Undertale", "Hyper Light Drifter" etc. All those games, among other indie games do something very different to big corpo. Titles.
Think about what could it be that makes your game special. Because just the package theming might not be enough.
Style
- What can I say, the animations and UI elements where quite beautiful, I loved the sprite work a lot and the Theme was fitting and nice.
- There is a point to be made about visibility of the play area. Similar how I managed to cluster up certain parts, this game can be harsh on the eyes at times. Darken your background elements. Take real life examples, the further something is away, the less information gets carried by light rays into your eyes. (Doesn't quite work like that, it actually get's distorted by sourrings, mostly the sky) Which is why far away objects appear blueish in tint.
- What I'm trying to say is, make an informed decision for colors. Backgrounds tend to be either lighter or darker than the playable area. Also use highlights to really show what is ground and what not, at least in cases where it's not 100% obvious. (I had trouble making out parts of the rails sometimes, at first.) This is not a huuuuge glaring flaw that destroys the game... But it's something to consider and I'll not it down for you here :)
- I loved the little Parallax effect btw.
Overall
This game, I feel, has quite a bit of potential still asleep! I critiqued it quite harshly in this review because you said you where planning on a Steam version. My overall Rating is obviously adjusted to this being a game for a Jam, you did very well in my Rating, actually. Only things I had to subtract was the easily getting stuck in every Level (which only just pushed the rating from "almost not 5" to "almost 5", because overall the levels where quite varied and there was a lot of different content, that got me thinking sometimes. Not much but enough for a Jam title.