I've read through this entire thread, nodding practically all the way through. I agree with most of these points unfortunately.
To clear up a few of the points that spring to mind:
Final level being too easy.
I remember putting the final level together, and I originally set up wave after wave of creatures coming from the side walls (i.e. you kill one, another emerges). The idea was, the further towards the final cavern you go, the more creatures would be triggered. In order to overcome this, you would need to build a 'safe path' with electric fences either side. That or arm all of your units to the hilt.
Unfortunately, it was deemed "too difficult" (by LEGO), and many of the creature triggers were taken out. In hindsight, I wish I had just left the old level files in the directory structure so you'd be able to recover that version of the level (I'd love to see it again myself after all this time).
Weapons/battle being generally rubbish
This one came from our overlords at LEGO. We were told to tone down the "violence" as it was a "family-friendly game". I haven't investigated, however I'd be interested to see if there are any remnants of the old Rock Monster "explosion" animations left behind.
Also, you already know of the planned Rockwhale. I would have loved for that to have actually made it into the game!!
A LANDSLIDE HAS OCCURED. A LANDSLIDE HAS OCCURED. A LANDSLIDE HAS OCCURED. A LANDSLIDE HAS OCCURED.
Sorry. Sorry sorry sorry sorry sorry. Did I apologize enough yet?
Also, one thing that *always* bugged me (and still does).
AN ENERGY CRYSTAL HAS BEEN FOUND!
I always hated the emphasis on the word 'HAS'.