The short version
Push Back's entire puzzle mechanic is a real-time fluid simulation: drag across the water and a visible current forms and dissipates exactly where you dragged, and the only tool you have to guide a stranded boat home is steering that current underneath it. It's a genuinely uncommon idea for a browser puzzle game, executed well enough that js13kgames.com's own archived results place it 4th out of 200 entries in 2019 and winner of that year's Mobile category outright. Testing confirmed the touch and mouse versions of that one core interaction both work identically — a drag on a phone screen and a drag with a mouse both produced the same visible turbulence pushing against the same boat — which is exactly the kind of claim this shelf exists to verify rather than repeat.
Biggest strengths
- The fluid simulation is not a gimmick bolted onto a conventional puzzle — it is the puzzle, and testing confirmed a drag genuinely produces a directional current with visible turbulence that dissipates realistically over a couple of seconds, on both a touchscreen and a mouse
- A real touchscreen drag and a real mouse drag were tested independently against the same level and produced the same current-creation behaviour, with no divergence between the two input methods
- js13kgames.com's own archived 2019 results are unambiguous: 4th place overall out of 200 entries, and the outright winner of that year's dedicated Mobile category
Biggest weaknesses
- The game canvas is a fixed square, and on a 390-pixel-wide phone that leaves roughly 450 pixels of blank white space above and below it — a real, measured waste of screen space on exactly the device class this shelf is built around, even though nothing is actually broken
- Some early puzzles are, in one judge's own words, not especially difficult ("I only played until the 5th I believe. It wasn't that hard"), so the challenge curve may take a few levels to properly engage a player looking for a real puzzle to chew on
- Only two public competition comments were archived for this entry, which is a thin sample to draw on for community reception compared to the dozens some other js13k entries attracted
Who it's for: Puzzle fans who want something that doesn't look or play like every other jam puzzler, and don't mind a short, contemplative pace
Our recommendation: Worth the first four or five levels on either a phone or a desktop; the drag mechanic is satisfying enough to be worth the visit on its own
8 / 10
A note before the review: the developer has not published a licence for this game — no LICENSE file, no statement in the README. It's published here credited to Erik Sombroek and Lomateron by name with a link to their own GitHub repository, and with a same-day takedown offer standing if either would prefer it not be hosted here.
Most js13k puzzle games reach for a familiar mechanic and dress it in a jam-sized twist. Push Back does something rarer: it builds its entire puzzle around a real physics simulation running live in the browser, and the puzzle only exists because that simulation is real. You control a stranded boat's journey home not by moving the boat directly, but by dragging across the water to create a current, and the boat drifts wherever the water pushes it. It's a genuinely different way to think about a "guide the object to the goal" puzzle, and js13kgames.com's own archived results back up that it worked: 4th place overall out of 200 entries in the 2019 competition, and the outright winner of that year's Mobile category.
A puzzle mechanic that is actually a simulation
Reading the shipped code confirms this isn't a scripted current painted along a fixed path — it's tracking real touch and mouse coordinates frame by frame and feeding them into what behaves like a genuine fluid solver. Testing this directly, a drag across the water produced a visible band of turbulence that followed the exact path dragged, then dissipated and drifted over the following two or three seconds exactly the way real water disturbance would, rather than snapping instantly back to stillness. That's a meaningfully different design foundation than "draw a line for the ball to follow," and it gives the whole game a soft, unpredictable quality that suits its watercolour art style.
Controls: touch and mouse tested side by side, no divergence
Because this shelf's entire premise is that touch has to actually work and not just be claimed, both input methods were tested against the same level rather than assumed equivalent. On the phone profile, a real touchscreen drag from one point to another created a current in exactly the dragged direction, visible as a lightening, foam-like turbulence trail. On desktop, the same drag gesture performed with a mouse produced the identical visual result against the same puzzle setup. Neither felt like the "real" version with the other as an afterthought; this is a fair, honestly mobile-first design, which lines up with its actual competition history as a Mobile category winner rather than a claim added after the fact.
The one real space-usage complaint: the game renders into a fixed square canvas, and on a 390-pixel-wide phone screen that square only fills about 390 of the available 844 pixels of height, leaving roughly 450 pixels of blank white space split across the top and bottom of the screen. Nothing about play is actually broken by this — the whole interactive area is present and correctly sized — but it's a real, measurable amount of wasted screen real estate on precisely the device this shelf is meant to serve well.
Presentation and a build-tree honesty note
The watercolour rendering is a genuine highlight — competition judge Jupiter Hadley called the graphics "lovely" and "so unique from other games," and testing bears that out; the water texture alone gives Push Back more visual identity than most jam puzzlers manage. One structural note worth recording plainly: the developer's GitHub repository ships a dist/ folder whose index.html references a g.js file that isn't actually present anywhere in the repository, and its asset paths are written as root-absolute (/g.js, /s.css), which would 404 if installed directly onto a site that isn't served from its own domain root. This review used the competition's own frozen build at play.js13kgames.com instead, which is complete and uses same-directory relative paths — the version actually played and judged in 2019, not an incomplete copy of the source tree.
Final verdict
Push Back earns its strong competition placement by committing fully to an idea most jam entries wouldn't attempt: a puzzle game whose only mechanic is a real fluid simulation, playable identically with a finger or a mouse. The blank space around the canvas on a phone screen and a thin public comment record keep this from a higher score, but neither undoes what's a genuinely original, well-executed puzzle game that backs up its Mobile category win with real, tested touch support.
Pros and cons
Pros
- The fluid simulation is not a gimmick bolted onto a conventional puzzle — it is the puzzle, and testing confirmed a drag genuinely produces a directional current with visible turbulence that dissipates realistically over a couple of seconds, on both a touchscreen and a mouse
- A real touchscreen drag and a real mouse drag were tested independently against the same level and produced the same current-creation behaviour, with no divergence between the two input methods
- js13kgames.com's own archived 2019 results are unambiguous: 4th place overall out of 200 entries, and the outright winner of that year's dedicated Mobile category
- The watercolour-style rendering gives the water real visual character rather than a flat blue rectangle, and a competition judge specifically called the graphics "lovely" and "so unique from other games"
- Twelve levels plus, per the developer's own description, a puzzle editor and additional bonus content, giving this real content depth for a 13-kilobyte competition entry
Cons
- The game canvas is a fixed square, and on a 390-pixel-wide phone that leaves roughly 450 pixels of blank white space above and below it — a real, measured waste of screen space on exactly the device class this shelf is built around, even though nothing is actually broken
- Some early puzzles are, in one judge's own words, not especially difficult ("I only played until the 5th I believe. It wasn't that hard"), so the challenge curve may take a few levels to properly engage a player looking for a real puzzle to chew on
- Only two public competition comments were archived for this entry, which is a thin sample to draw on for community reception compared to the dozens some other js13k entries attracted
- The developer's repository ships an incomplete `dist/` build (referencing a `g.js` file that doesn't exist in the repo) with root-absolute asset paths that would 404 if installed directly; this review used the competition's own frozen build instead, which is complete and correctly path-relative