I love the game, it remember me the simpsons arcade, the dificult is ok (a little easy, but is ok).
I have some sugestions (the game don't need them to we awesome, but don't matter 
:
1 - Put Transparencies in closet objects of the scroll (windows of the veicles).
2 - Animations in the objects of the scenario, like the old computers.
3 - A Zoom effect i map.
4 - Another way to open doors, i don't understand the color swith's to open the doors)
5 - Another button to talk with zombies, L or R buttons, because A interfer with shoots when we don't want to ask them.
6 - Another's items in the scenario, like cats running and screaming, dogs, etc.
It's all for the moment 
i will take a look at making objects which are in front of you transparent and see how that works. i kind of like not being able to see exactly what's behind every corner, but some objects, like the dump truck, are pretty obstructive. i'll be honest, i'm probably not going to animate many objects just because of the time, it definitely would be fun, but it's probably not going to happen.
now with the doors, is it a language issue? or is it just too unintuitive? i do have another idea for the doors which would involve giving you a set of keys which you would have to select the matching key to the lock on the door based on the shape of the key. so instead of matching colors, you would be matching shapes basically.
i'm not sure what you mean by zooming in the map. and Mr Matsusaka, you
can check the map from the pause menu unless you are in a building (or in the sewers), but on any street, and in the mall, you can pause the game and see your exact location on the map (in the previous wip, it would show which street you were on, but not your exact location).
the reason i did not map anything to the "R" or "L" buttons is that i find those buttons to be very awkward to press on the wiz. but i think you are right, i think i will separate the talking onto another button to avoid the conflict of trying to do an action with the random walking of NPCs. that will also free me up to make it so you don't have to be right on top of the NPC to start a conversation, i think i'll just make it so that when you hit the "talk" button, it will show a list of the NPCs who are on screen at the moment, and you'll be able to select the one you want to talk to. that would also allow me to make it so you can still talk to people who have already joined you when new dialog questions are unlocked.
Mr Matsusaka, i like the idea of marking characters who you have already met on the map. i'm not exactly sure how i'll implement it, but i'll add it to the ever expanding to-do list.
and just so you guys know, i am planning on making it so you can save your game. that's probably one of the last things i'll do, just so that i know everything that will have to be saved for the save state.
oh and i almost forgot, superior versions of both the caanoo and PC versions, as well as the wiz version are now available on the
projects page. the wiz and caanoo are the same as the current versions on openhandhelds.org, but the PC version is more stable than the one i originally posted.
