My Son Cried When It Worked. So Did I, Honestly.

By Dominic Farrell-Osei

I should say upfront that I am not a patient man. I work in logistics. I eat lunch at my desk. I have strong opinions about the correct way to load a dishwasher. I am not, by nature, someone who sits on the floor for two hours assembling a marble run with a seven-year-old.

And yet. Here we are.

The Problem with Screens

My son Theo had been on his tablet every evening for about three months. Not excessively — an hour, maybe ninety minutes — but it had become the default. The thing he reached for the moment dinner was done. And I noticed that he wasn't really doing anything on it. He was just... consuming. Videos, mostly. Passive, glazed, unreachable.

I'm not anti-screen. I'm not that parent. But I missed the version of Theo who used to build elaborate Duplo cities on the living room floor and narrate them to himself in a running commentary. That kid had gone somewhere, and I wanted him back.

I started looking for something that would pull him away from the tablet without feeling like a punishment. Something that required his hands and his brain simultaneously. Something with a payoff dramatic enough to hold his attention.

Why GraviTrax

I'd seen GraviTrax mentioned in a few places — a parenting forum, a gift guide, a comment thread where someone described it as "the toy that made my kid forget the iPad existed." That last one got my attention.

We already had the GraviTrax starter set, which Theo had enjoyed but outgrown a bit — he'd built the same configurations so many times he could do it from memory. The PRO Vertical Expansion was the obvious next step. It adds a whole new dimension to the system, literally: vertical elements that let you build upward, creating drops and loops and momentum shifts that the base set can't do.

What sold me was the engineering logic behind it. This isn't a toy that does the thinking for you. You have to plan the track, account for gravity, test it, fail, adjust, test again. It's physics made tangible. For a kid who was starting to show real interest in how things work, it felt exactly right.

I ordered it the same evening: GraviTrax PRO Vertical Expansion Set – 33 Piece STEM Marble Run Toy.

The First Build

It arrived on a Saturday, which was fortunate. We cleared the dining table — a significant undertaking — spread out all 33 pieces, and Theo immediately started sorting them by shape without being asked. That was the first good sign.

We spent about forty minutes on the first attempt. It didn't work. The marble got about two-thirds of the way down and stopped at a junction where the angle was slightly off. Theo looked at me. I looked at him. I expected frustration — he's seven, frustration is his default setting when things don't go to plan.

Instead, he said: "I think it's that bit there. The blue one."

He was right. We adjusted it. We ran the marble again.

It worked. The marble dropped through the vertical section, picked up speed, looped around the base, and landed in the collection tray with a satisfying click.

Theo made a noise I can only describe as a victory roar. I may have punched the air. My wife, who had been watching from the doorway with a cup of tea, said "finally" in a tone that suggested she'd been waiting for this moment for some time.

What Happened After

That was four months ago. The GraviTrax set has been rebuilt approximately eleven times. Each version is more ambitious than the last. Theo has started sketching his designs on paper before he builds them — unprompted, entirely his own idea. He's begun explaining the physics to his younger cousin in terms that are, frankly, more accurate than I could manage.

The tablet still gets used. I'm not going to pretend otherwise. But it's no longer the first thing he reaches for. Some evenings he goes straight to the dining room and starts building before I've even finished clearing the plates.

That's the difference. Not dramatic. Not overnight. But real.

Who This Is For

If you have a child between roughly seven and fourteen who likes building things, problem-solving, or just watching something work after they've made it work — this is the toy. It's also, I'll admit, genuinely enjoyable for adults. I've built sections of it on my own after Theo's gone to bed. I'm not ashamed of this.

It works best as an expansion to the existing GraviTrax system, but the PRO Vertical set is substantial enough to be a meaningful standalone purchase too.

Browse the full range in our Toys & Games collection and Toys collection — there are other GraviTrax sets and expansions worth exploring once you're hooked, and you will get hooked.

The GraviTrax PRO Vertical Expansion Set is available now. Buy it for the kids. Stay for the engineering.

Dominic Farrell-Osei works in logistics, lives in Bristol, and has recently started sketching marble run designs on Post-it notes during conference calls. He considers this a net positive development.