Adding replay valueThe problemIt has been in the back of my mind for some time that the replay value of the game may have been quite minimal. The reasons for this are because there are two things that may happen on any level, you may either finish it, or not finish it.
There is no in-between. Therefore, if you finish a level, you have no incentive to come back and improve, as you have finished it, there is nothing further to gain.
There are several subtle mechanics in the game that allow this style of play. When crates leave the level through an incorrect exit, or are destroyed, replacements are put into the queue and re-appear. This allows you to retry, but at the same time does not allow for improvement to their gameplay by the player to be properly recorded.
The solutionAs a solution to this problem, i have taken a look at the way certain games such as angry birds and cut the rope encourage replay value of levels. By 'borrowing' the way they handle level replays i have hopefully increased the replay value of firework factory.
The solution as i see it is fourfold:
1) When creates are destroyed, don't automatically place new crates into the queue.
2) Treat the remaining money as a pot of bonus money to be given to the player at the end of the level - it is no longer a game over condition to run out, it is just not good for your ability to buy powerups.
3) When all crates are either destroyed or sent to the correct location, the level always ends. The percentage saved is calculated. Each level has a fixed percentage that is needed to be saved to advance to the next level. This is very rarely 100%, so there is always room for the player to go back and improve their efforts. As well as going back to improve their score, they may also go back to gather further coins to spend on power-ups, even on levels that they have previously aced.
4) Store the user's best score for each level and display them on the level selector.
On completion of the level, a different screen is presented to the user dependent upon failure or success, as shown below.


I am sure Miguelito will have ideas on how to improve the look of this basic screen and i am sure nickproud will have some ideas on music he will want to play on either occasion

Stay tuned for more updates!