This is pretty good, the screen shots don't do it justice. It's got that simple yet addictive quality and I actually like the simple design (not such a fan of the music but that's what volume control is for).
I've got to level 1.9, which took me longer then 20 to 30 minutes, and I thought it played really well, challenging but not too frustrating.
The collision detection's a little iffy when the circle hits the corner of one of the blocks. There were jumps that I thought I had made, the circle fell through the block and sometime I was travelling on thin are when I came off the right had edge of the block. Also, when I hanging underneath and jumped just as I reached the end of block the circle jumped up instead of falling, which felt a little incongruous.
The other minor issues were:
a bit at the end of level 1.8 where the player has to roll along the bottom of the screen to ge to the exit. This just seemed inconsistent when previously I was having to jump over the gaps to avoid falling through them.
in level 1.9 (which I haven't completed) there's a "jump boost" that's just floating in mid air. It might look a bit better if there was a block underneath it (I'd say that for spikes and other features as well).
I also think it might be an idea to add a grey or cyan stripe to the circle so the player can see it rolling. But I'm only suggesting that as you've used colours in the other levels so I don't think it would ruin the look.
One other thing I'd say, and I might be wrong, is that I think it would be better to have fewer but well crafted levels than lots of levels where a lot of them feel like padding. I felt you're other game Ryder was like this, some of the levels were really good but others felt a bit scrappy as if you were just reaching to get 100 levels and anything would do. You can always add more levels through updates or sequels.
But, yeah, this is really good and would definitely download the finished game.
