One of the selling points in the description was "A must read for anyone interested in building their own platformer ". That's certainly me. As a programmer I was hoping for a real "deep dive". Perhaps a serious technical analysis of jumping mechanics and implementations. Or at a minimum maybe some plotted jump paths on the game screenshots.There was none of that. The book is full of shallow and obvious observations. Let me share a few examples:Section 6.3 "The Factors of Jumping"Joshua gets a little technical and outlines the "DNA" of a jump. He lists a series of "factors" that would be useful for a designer to know. However, I noticed some glaring omissions: 1. There was no mention of "gravity". Only ascending and descending "speed" were given. While I'm sure that some platformers don't bother with physics, many use physics based formulas that certainly take gravity into account. Look up the GDC talk "building a better jump" to see what I mean. 2. Where was the "factor" for "coyote time"? This is the time in which a jump can still be triggered after falling off the edge of a platform. This has been a staple in platformers since at least the original Super Mario Bros and it wasn't mentioned at all in the book.Section 7.6 "Fall Damage"This whole section can be summed up as "In some games you take damage after falling for a while, and some people don't like that". This is not the depth I was expecting from a "deep dive".I suppose this book may be useful in helping designers better communicate their ideas to programmers, but even in this respect it seems much more cursory than a "deep dive". This feels more for aspiring game designers that haven't played many games.Also the price is quite steep for 152 pages, where most pages include game screenshots.