Nice example, and it works great
[quote:j8d64kv3]Actually a custom engine doesn't give you more control at all.
Sure it can, if you make it that way. It all depends on what you're going for. Anyway, there's nothing wrong with making a custom platforming engine, and yeah one of the benefits is you can add as much control as you need, or don't need. But unless you're doing something non-standard with your engine, you might just be wasting time.
For basic things like gravity and collision you might as well use the built-in platform movement, because it already does it for you. You can apply the fancy inverse-square math to the platform movement's speed, thus enhancing the basic platform movement. It's just something to keep you from reinventing the wheel every time you want to make a game.
Generally speaking, the platform behavior will cover all the basics (and then some) for what you need it to do, and unlike the MMF platform behavior it's very well put together and flexible (it better be, David's been tweaking it for like two years ).
The only time you'd really need to make a custom platform movement is if you need special logic/drawing separation like kayin for his IWTBTG engine, or if you're making something like Sonic or Flashback that has non-standard platforming functionality. For everything else you can pretty much start with the built-in behavior and just add the features that you need to it (like swimming or ladders or double-jumping or whatever).