Pac-Man itself is a good basis however Arcade3D fails to be fun, intuitive or automate the right parts. It's derivative to the point of probably being copyright infringing (I am not a lawyer; this is not legal advice), but it's not worth the rightsholders of Pac-Man suing over. It's also not the first Pac-Man game for Minetest.
However, with a bit of a clean-up, the game could be good. Work has clearly been put into the visual art, I chuckled at the player model in a good way and the use of spheres for pills seems sensible, including not having too many polygons.
The idea of making your own arena is defeated when you realise the game has no way to spawn ghosts and pills for you. A good level editing experience is possible within the Minetest engine, so I exhort the developer to make better tools, which would be marking spots for the ghosts and pills to spawn, being able to start/stop a game intuitively, and of course not leaving the player inside the arena wall when placed.
Pacmine, part of myArcade, has the game starting feature down pat: right-click a starter node. The pink gates in Arcade3D make no sense, something myArcade handles better by having you right-click a node to start a game. However, Pacmine also suffers the issue of poor pill collision detection with server lag, so having the pills as nodes is better for that. Some comparisons to Pacmine wouldn't be helpful; Arcade3D being its own game is fine.
Conclusion: The promise of being able to make your own arenas is enticing, but as-is the game fails to deliver a good Pac-Man clone or level editing experience.
Room for improvement: The minimap should be enabled by default, corridors should not be 2 nodes wide, because the pills end up on one side and not the other. The game should detect when a level is finished. The ghost AI needs to be much, much better and eating ghosts needs to work (punch or collide, I don't care).
Recommedations: Since the game has high walls, the minimap should be toggled on by default; that way you can see what pills have been eaten. I wish the ghosts would also show there, but that's not possible in Minetest (yet?). Also a way to make teleporting sections in the level editor.