The idea is to fill the screen with 4's. You can combine adjacent numbers. Or you can split a number.
Each grid size is 2x4. Which is a shame because after a while the puzzles become too repetitive. Maybe the grid size changes, but there's no way for me to find out.....unless I keep doing them.
Here's another thing that bugs me: when I select next puzzle, why do I have to then click 'play'?
Some things that work well: good graphics. Good concept.
Overall - play it only to see how fast you can solve them. If you manage to do even 300 of the 1000, please contact me and explain if the game gets any better.
Update July 28:
I just tried to leave a comment on your blog, but it doesn't work. So I decided to write an email.
First I want to say: I'm reading your blog for a while and I really like your app reviews. How you can find so many great puzzle games? Keep it up!
Ok, now back to your blog post about Delta. I downloaded it and now I'm stuck on level 313. (Yes, I have "skipped" some levels with extra moves, too.)
And yes, I can answer your question (Does the game get any better?): Yes it gets better.
On level 255 the grid size gets bigger. Now it's 3x4 and you need more moves to solve the levels.
Although some levels are quite similar, I like the game. Thanks for your app review!
P.S.: Sorry for my bad English. I'm from Germany. ;-)