Great new build Simone, thanks again for listening to all suggestions!
Just a few small refinement requests and a couple of ideas to enrich the game experience:
Presentation
almost perfect now, just a couple of timing issues:
- attract screen (e.g. last played stage): this is still a bit too short and is often over before once brain has adapted to it. I understand that it lasts until the first alien hits the bottom. I like this element, but it tends to extremly shorten the attract screen at times, IMO.
Suggestion: after the first alien has hit the bottom, there will be no more entering the screen from top, and the attract screen will end once the last alien has hit the bottom.
The alternate (second-choice) remedy would be to set a fixed longer time period for the attract screen.
- game over/ continue screen: optimal solution for the continue option. Only small problem is that it reverts back to the title screen with the end of the game over sequence, which leaves very little time to decide on continuing or not ( especially after a frantic game where one first needs a few seconds to digest the experience).
Suggestion: delay the return to the title screen by a few seconds after the end of the game over sequence.
Suggestion2: flash the continue message rythmitically so the player has a clue when it will end by observing the number of flashes.
Catch level
- catch effect: thanks Simone for considering and explaining the collision routine problem. Fair enough! Clearly we're expecting magic from you, but not the impossible!
Suggestion: Building on your flash effect (which in light of the limitations does now indeed appear as the smartest approach), maybe you could enhance it by either a) introducing a "desintegration" animation for the aliens (after the flash) or b) cycle the flash through several increasingly brighter shades of white.
Not sure whether it is technically possible and how effective it would be in practice, but it might be worth a try...
- catch indicator: just to support Nathan's suggestion. While it's possible to indirectly keep track of the misses (by counting the miss sounds or checking the score), the indicator would add further arcade polish to Lead.
An alternative idea to the percentage counter would be a message like "3 Misses from Perfection".
Just an idea, no preferences here...
- bonus intermissions: ok, here's an idea which should not be too difficult to implement but would further enrich the game experience and thicken the game "story"

:
In case of a perfect catch, two of the earlier shot aliens (e.g. from stage 1 for catch level 5, from stage 6 for catch level 10, etc.) would enter the screen on top, holding below them a "score capsule" indicating the bonus amount (think of the Lead1K capsule from the options screen, filled in, with the score amount displayed in black).
They would travel until above the status text display (e.g. "Stage cleared/Congratulations/Perfect"), leave the score capsule, and then shoot of to the top (same effect as the player's ship after finishing a stage).
Thereafter the normal stage clear intermission would set in.
- increasing bonus amounts. Not much to elaborate here - would be a nice motivation if the bonus score would increase with each catch level (for instance: 250 - 500 - 750 - 1000)
Graphics
- I'm sorry to bring this up again, Simone, but...
Would it be possible to design different icons for the ship upgrade and score bonus? It just feels a bit unpolished to have the same smart bomb symbol for all effects...
...would be

!
Cheers, Eric