Batman, Gandalf the Grey and Marty McFly take a trip in Doctor Who's TARDIS. Then things get really weird.

No, this isn't a deleted scene from Pixels or Wreck-It Ralph. This is Lego Dimensions, the latest entry in the "toys-to-life" market tying together video games and physical toys, which is taking over store shelves and threatening to bankrupt parents and fans alike.

The premise behind toys-to-life is simple enough: a video game comes with a toy figure and a special pad that connects to your video game console. The pad scans codes on the bottom of each figure, which can bring a digital version of the toy onto the screen for you to use, and unlocks new features or levels in the game itself.

While the video game itself usually comes with a handful of figures, the big draw is the extended line of dozens of supplemental figures to add to your game.

Because of this, a single purchase can now spiral into a figure-collecting binge worth hundreds of dollars.

Lego Dimensions Back to the Future pack

An example of a Level Pack for the game. Each figure is set on a special base that connects to the game when you place it on the larger Toy Pad, which connects to your video game console. (Traveller's Tales/Warner Bros. Interactive)

Gotta buy 'em all?

Gar Wan Toy, co-owner of the A&C Games video game shop in Toronto, likens the figure-collecting aspect of these games to Nintendo's Pokemon series, where players capture and collect monsters. This time, though, the monsters are real-life toys, and cost real money instead of a Pokeball or two.

"It's just like [Pokemon's catch phrase] 'Gotta catch 'em all,' except now it's 'gotta buy 'em all,' " he told CBC News.

After Activision kickstarted the genre with Skylanders in 2011, it's become one of the fastest growing segments of gaming today. Activision reports that Skylanders sold more than 250 million toys, making over $3 billion in total game and toys sales as of 2014.

The Disney Infinity series soon followed suit, bringing Mickey Mouse, Star Wars and Marvel Superheroes to the genre. Nintendo joined the fray in 2014 with its Amiibo figures, giving physical form to classic characters like Super Mario and Princess Zelda.

According to an NPD report from May, parents spent an average of $170 on toys from Skylanders, Disney Infinity and Amiibo in the first half of 2015 — a 19 per cent increase compared with last year. Two-thirds of respondents said they were likely to buy a new game or figures in the future.

NPD games industry analyst Liam Callahan sees the most cross-generational appeal in Disney Infinity's Star Wars line of figures.

"I could see a scenario where parents are buying some of these toys really for themselves. They want to have that experience with their children from a nostalgic point of view with a toy or character from the earlier films."

Disney Infinity Star Wars figures

Disney's Infinity series has exclusive rights to Star Wars figures in the toys-to-life gaming genre. (Disney/Facebook)

Costs can quickly rack up

Even without the monolithic Star Wars franchise, it's not hard to recognize Lego Dimensions' unique appeal: actual Lego sets.

The starter set includes the video game itself, three Lego minifigures (Batman, Gandalf and Wildstyle) and the Toy Pad, which connects to your console but also comprises an intricate Lego "portal" structure. All of this costs $110.

Supplementary sets featuring other intellectual properties such as Jurassic World, The Simpsons and Scooby-Doo cost anywhere from $15 to $30. If you want to get every pack in the first wave that launched late September, you'll be in for $445 before tax. At least two more waves of figures are planned for the next six months.

Anyone interested in the other games will have to double down on the starter kits, too: Except for a select few Skylanders toys with added Nintendo Amiibo functionality, no toys-to-life figures are usable across different games.

But is it good?

Parents might have hoped that Lego Dimensions ended up as a hollow cash grab, allowing them to write it off and avoid the pile of related merchandise entirely.

Bad news for your bank accounts: It's actually quite good.

A dimensions-hopping supervillain named Lord Vortech (voiced by Gary Oldman) plans to take over the Lego universe. Batman, Gandalf and Wildstyle forge an ad-hoc partnership to save the day.

The Force is not with this one: Despite Lego and Star Wars' longtime brand synergy, don't expect any Jedi to appear in Lego Dimensions. IGN reported in June that Disney VP of production John Vignocchi said Star Wars products in Lego Dimensions would "cannibalize" Disney Infinity business. So stick with Infinity for your toys-to-life lightsaber duels.

Mashing together over a dozen classic franchises like this might be a cheap trick, but there's something undeniably fun and irreverent when you see Batman run into The Wizard of Oz's hapless Scarecrow, and mistake him for the bat-villain of the same name.

A metric tonne of superstar actors reprise their roles for the game, including Elizabeth Banks as Wildstyle, Michael J. Fox as Marty McFly and Chris Pratt pulling double duty as Emmet from The Lego Movie and Owen Grady from Jurassic World.

Other than the main cast, though, they're mostly cameos with a few minutes' worth of cutscenes re-enacting some of their most well-known scenes.

The Toy Pad is split into three sections that can hold your mini figures, and you'll have to solve several simple Simon-says-type puzzles moving the figures between each section to progress through the game. So make sure to keep it within arm's reach.

Lego Dimensions 01

Lego Dimensions' biggest selling point is probably the crossover potential of over a dozen franchises including Scooby-Doo and Jurassic World. (Traveller's Tales/Warner Bros. Interactive)

It's a simple, easy-to-understand mechanic that makes it perfect for co-operative play on the couch. Parents can play the game on the television while a child manoeuvres the figures on the pad, or vice-versa.

Visually, it can be a bit of a mess: With explosions of Lego bricks and wide shots of ruined cities, it's harder to keep track of where you are on the screen than you might like.

But the Lego functionality and light-hearted story raise up what might otherwise be a slightly above-average game into a great way for parents to take an active part in their kids' gaming time.

Just be prepared for a pricey entry point — and the threat of being pulled into the nostalgia-fuelled merchandise machine yourself.