sorry to get started on this a bit late, but fwiw I requested some earlier beta versions to test and sort of got ignored. I've now had a chance to play through a few times, and finally got the stats page to load up (I'm #4! woohoo!), and I have a few observations:
1. awesome! stats are a very cool feature, and the game runs quite smooth. the fullscreen mode is another nice addition, and TNM is pretty amazing. all in all, excellent work! gr++ is very close to my heart and you have no idea how gratifying it is to see it running on my new powerbook
THANKS!!!
2. control still leaves something to be desired. mouse control is perfectly responsive, but the window mode does not 'grab' the mouse in the same way the PC version does... or something... Unfortunately I don't have a PC up right next to me that I can check on, and maybe my memories are based on the fact that on the PC version you can resize the window. I often would resize it to 'full screen', despite the scaling artifacts it imposes on the graphics. This means that there are no 'dead zones' in the mouse control -- when you get the ship to the edge of the window, mousing back in the opposite direction is IMMEDIATE. In the current implementations of OSX gr++, it seems unavoidable that the mouse can exist beyond the window or active game area. This means you have to mouse back into the game window before the controller does anything! With all due respect, I really think this is hampering the gameplay significantly. The few moments spent trying to get the controller to 'work' can make all the difference in life or death, and it doesn't feel fair to die because of a control issue...
3. playing in 1280x854 mode on my powerbook 1.3ghz causes a slight graphical error in the full screen mode: the lower ~15 pixels of the screen flash black and white in rapid succession. This only occurs to the right of the play window (not on the left side). Just out of curiousity, what is the point of offering different full screen resolutions anyway? They all seem to display the same on the powerbook screen, and I'm not sure if there is any filtering going on at higher resolutions or if it's just me and a placebo effect..
4. in relation to 2 & 3, the full screen mode looks a bit .. empty. I love the feature, and wouldn't ditch it, but how about a border or background maybe? A better option would be to scale the window to full screen width -- not only does it make the whole screen active (rather than bordered with black bars or whatever) but it also makes gr++ more responsive to play in some ways. by providing more width to the display, there is more interactive play area on the screen; more mouseable area, and provides more control over left-right player movement..
5. sound samples are still a bit funky. this issue was raised
here, and I've
posted some revised samples here. basically there are a couple of timing and volume issues that I believe are sort of confusing the audio landscape slightly. don't get me wrong -- I love the samples and just the general 'sound' of gr++, I just feel that a few tweaks makes it much easier to note the _truly_ important in-game actions like split snakes and sheepie drops that occur offscreen.
6. is there something to deal with stats being screwed up by a player abusing slowdown? if I run the game in windowed mode with a few things going on in the background, gr++ can run at 50% speed or whatever. is this reported in stats? at this speed, I could accumulate a pretty impressive score with a somewhat unreasonable advantage...
7. a pause button is really necessary... F10 is one of the default Expose keys so another should probably be chosen, like 'p'
8. I have to agree with the post above where being able to Alt-Tab out of the game when paused (or maybe automagically pause the game) would really be a big feature. It feels a bit .. weird .. not being able to pause or switch apps or anything...
gotta say, though, this whole OSX port really makes my day. Really great work!
Maybe the final version could store settings (e.g. full screen or windowed.) Allow a user option to stop GR++ phoning home, even if it is just for high-scores! What? Me, paranoid? 
I will be doing this once I can actually buy the game!
Will the high-scores, slots, etc. be saved on exit in the full version? They reset at the mo.
I'm actually rather crap at GR++
