Before the game loads a screen pops up saying unregistered then some load and play fine others all that happens is I get a demo of the intro but nothing else and some won't load at all it just says that it needs to be registered.
Some games do require a registered WHDLoad (a keyfile). For instance, the game Fears for AGA Amiga's requires a key to work. Lotus Espirt Turbo Challange works without the key, but you'll be racing against yourself! (no other cars on the track...until you have a keyfile that is)!
Most games work fully without the key, but you do get the annoying start delay, so I'd recommend registering.
