As others have mentioned, prologue and epilogue comic cutscenes soft lock the game - this can fixed though!
1. Go to Finder and find Diner Dash 5 Boom in your Applications section or in a folder for MacGameStore. Right click the icon and click 'show package contents.'
2. The folder you're looking for is hidden for security reasons. First click on the Contents folder then resources and enter on the keyboard at the same time Command+Shift+. (the period key.) You'll see a lone new folder called 'Game.'
3. You'll find the base game which has all the info for the game to run. Like last time, right click, 'show package contents,' and go into contents. Now go to resources and then assets. restaurants.
4. Inside the restaurant folder are the files for each location in the game; all of them have one folder called 'Comics' with a .swf file for the beginning and ending of each. You can either outright delete the folders each or just the files inside the folders themselves.
5. The only issue you'll have now is during the loadup with the same 'missing plugin' - I'm sure there's another file you can delete to outright skip it, but you can just click anywhere to skip it (it's probably just the game company logo.)
In terms of gameplay, PlayFirst gave some new variety, but wasn't tedious to work with like the last two. Too bad this was their last PC first Diner Dash game.