I've been slowly progressing through the English version of PhantomGate for about a week now and the game is pretty good in terms of platform puzzle exploration. The art is nice and the mini puzzles in each stage is a nice touch. I can see myself playing the game for a good month or two unless I end up rage quitting from the crazy Gacha. I've rolled so many times and haven't received a special rainbow prism unit. I should've rerolled or something, but I'm already too far in the story.
The game gives off a Child of Light vibe so if you enjoyed playing that, you might want to try the game out. It's only available in the Australia, but you should be able to get by that by just creating an Aus account in Google Play or App Store. If you're on Android, just take the easy way out and download the APK. I'm still on the fence on whether or not I would recommend the game since it has two kinds of Gacha system Monster and Equippable Gems. It just seems like it's too hard to progress fast unless you roll something nice and shiny that can evolve to six or roll some awesome gems in the shop. Sure, you can evolve some other stuff, but materials are hard to farm and before you know, you evolved something crappy. If you don't mind those, then go ahead, the music and puzzle stuff is great. I hope you get a shiny prism rainbow character XD!
Game Site: http://phantomgate.netmarble.com/en