To put it quite bluntly, Peglin is what happens when you take Peggle's orb-chucking gameplay and mix in some random encounters and progression elements to help spice everything up. The end result, as I've detailed in my preview, is a surprisingly interesting and addictive little rogue-like, even if the Early Access version is somewhat limited in terms of content.
You can get a pretty good idea of what all of this looks like in action, as well as how the gameplay even works, through the recently posted launch trailer. Have a gander:
If you're still not sure where you stand on the whole idea of a peggle-based rogue-like, it's also worth mentioning that Peglin has a free demo available. The demo contains the entirety of the first world and showcases pretty much everything Peglin has to offer, so I'd definitely recommend giving it a look if you have an hour or two to spare.
You can check it out, as well as learn more about Peglin's Early Access plans, over at Steam. Have fun!