Looking great, that gameplay is TIGHT (wanna steal it... ah, temptation ). Three things, which are totally just my opinion:
1) The different pixel sizes in gameplay seem to mush the neat visuals a little, such as those pipes with the saws in them - I think it would look neater if everything had the same pixel scale.
Was it just the saws you noticed? They're only 32x32 (most sprites are either 8x8 or 16x16). It does have an effect applied to them, so that might be what's causing them to look a little odd.
2) A similar "out of place" thing might be the rotating and fading green blocks when you smash them - perhaps a neat pixelly smash effect might look better, like spawning some particles, some 2x2px, some just a pixel, I think it might look great.
This is a great idea! That's something I should be able to implement pretty easily too! Thank you for that one!
3) As you are aiming at a mobile platform being careful with the shaders might be a good idea.
We're talking about the portal aren't we? You are correct, that has an effect applied to it...and I should probably remove it and redo the portal sprite, to keep it consistent and running well.
There is 1 effect that I want to keep at all costs, the little blur at the start and end of levels. I very much like the feel it gives. The rest I can probably k-bosh. Thanks for the input!