New this build: editing values in the debugger! This improves the utility of the debugger greatly, since you can simply click a value, type something in, hit enter, and immediately see the result in real-time. This is also great for experimenting and tweaking, such as getting things like all the particle effect properties fine-tuned with immediate feedback. It's a powerful feature, and consequently is not available in the Free edition - another useful bonus if you have a license!
Other improvements include the ability to step a single frame while paused (the engine simulates a dt of 0.016 - the value of delta time at 60 FPS) so you can inspect the behavior of the game frame-by-frame, such as to watch how a collision is handled; and the missing global and static local variables are now shown and can be edited!
We have more improvements to the debugger planned. We've read some suggestions on the forum and have some of our own other ideas, so we'll keep making improvements over the next couple of betas. Stay tuned!
Also if you're based around London (UK), check out our upcoming Scirra Night on 27th September!