The donation process is automated and emails are sent as soon as donations are made. There are a couple of reasons why your email hasn't come through:
If you have made a donation using eCheck: then the email will be sent when the transaction has been completed. Paypal send me a confirmation message when a pending transaction completes and it automatically sends an email to you.
Junk Mail: It may be in the junkmail folder. Also, check your spam settings as it may be getting automatically discarded. I am trying to improve the email content and headers so that this is less likely to happen.
Pushed Mail: Building on the junk mail issue above, if you get mail pushed to a device (iPad, smartphone etc), email providers may only push your inbox mail through leaving your spam folder on the servers without you ever seeing them. This is generally a good thing... unless my email gets lumped in with the rest of the spam. To check, log in to your email client through your browser and see if there is a spam / junk folder with my emails in it.
Blocked: There are a couple of internet service providers (ISPs) that are more 'cautious' than most and it seems that at this stage they just won't accept my automated emails. In this case I can manually create a password if you email me. This doesn't solve the wider problem but at least you can play the games.
CPU Load: If you run an older PC, an underpowered handheld device or have a lot of other programmes running, animations using the jpeg option in settings can flicker, run slowly or give a blank screen. Try changing to the gif option in the Menu->Settings section.
Preload Failed: All images and animations are set to preload before they are required. Sometimes these timeout and when they are required in the game, will be redownloaded. This generally gives a blank screen while it loads. Some animations are up to 10 Megabytes (for gif) or have 60 images (for jpeg) so loading times can be long. This is usually resolved playing through a second time as all images eventually loaded while playing through the first time.
Slow Connection: The game is big and slow connections may suffer from a distinct lag. Once all images have been cached, this should not be an issue any more.
Global Issues: Different countries and other interested parties will play silly buggers with the networks, testing nations and corporations security. This plays havok with download speeds. There has been one instance where animations were disrupted from getting through the network during a large cyber attack.
Local Issues: I may have screwed something up. If you believe you have a specific problem then let me know. The more information I have, the better I make these games.