There are several ideas too numerous to add on the main title such as randomly generated levels, levels editor, mini games, acievements a stats panel and top scorer etc

I realize that this game is several years old now, but it could be improved a lot by making the levels randomly generated (if that's possible), this would ensure that the second and third play throughs were different to the first time play through as well as give the game a much higher replay value. I'd also consider adding mini games at the end of each stage and also fractoring in a timer. You could create a few different modes and give awards for various achievements such as completing levels in specific times, have a 'fastest time completed' and extend that to different profiles, so whoever completd the level in the fastest time gets their nameslit up at the end of a level. You could also include various point landmarks and maybe some different skins for the blocks that you can select from the options menu. I'd also consider adding a hint button for those who are finding it hard to finish the last few levels. Such things add incentives to the game or help those that are frustrated at not being able to progress. You could also add hidden levels that are unlocked only by achieving certain parameters. You could even add a story line and power ups that are upgreadable. All the above added togther would add much more replayability as well as update the game to the present as most games of this type now have at least one or two of the suggestions I've made. :)

I'd also include a better help file with more examples including strategies for winning.