I just finished my first game for the Android, Backyard Zombies. I used the Unity3D game engine and it was really a lot of fun. If you wanna check it out there's also a free version

Here's my next idea for a game:

I haven't figured out how the main game play will work out, but I think it should be similar to Doodle Jump.

Basically you collect monsters that you find along the way and can later view them in your collection.
Also you collect energy orbs or whatever that you will use to breed two monsters together, unlocking a completely new monster. This would allow for some cool mixing and matching with monsters that you collect!
I guess to unlock new levels you would have to have a certain amount of monsters unlocked, and with these new levels you can encounter new monster types and what not.

I love the Doodle Jump game play because it's addicting and would be perfect for randomly spawning monsters, but I'd like to change it some how so it's not the exact same. Any sugestions? What do you think about this idea?

Hmm. I like monster breeding games in general, but I've always hated those jumping games. But I guess I'm not in your target audience anyway, since I don't have an Android.

Best Monster game was Dragon Warrior Monsters.

Best way to make it not always the same is to add extra changing variables. Make the background random, the theme random, create powerups and make them random. More variables equals more combinations equals more types of gameplay. plus its always good to make the amount of monsters ridiculously high. The game I'm working on has a creature collector feel to it and i plan to release with at least 200 and a definite plan for expansion.

You've got 2 separate and distinct sets of mechanics there:

1. Collecting and breeding monsters; the goal here in general to built as complete a collection as possible, and perhaps to experiment with interesting combinations.
   
2. Platform-jumping; the goal here is to jump to successively higher platforms, and to avoid falling to your death.
   

I think for the game to really feel cohesive and complete you would need to somehow provide some sort of feedback from the monster collecting and breeding into the jumping game. Consider for example that in Pokemon you use the monsters you have collected in battle, and each have different strengths and weaknesses, resulting in your collecting, training and breeding having a direct and meaningful impact on the rest of the game.

Perhaps as an example you could actually play as one of your collected monsters chosen at the beginning of each level, with different ones having different capabilities (higher jump, wings making it fall slower, able to pass through the bottom of a platform when others would have to go around, etc.) that impact your jumping game-play.

Well, I haven't got anything against either type of game (and actually, as far as monster breeding games, I like the a lot. In fact, there was a pretty good game a while back that made you mix animals to create monsters. All I remember from it is a tiger with claws and that it was set in somewhere snowy, at least the first few levels. Anyone got a name?) but I think you're going to need to think of further utility for the monsters.

Right now, as your idea stands, the monsters serve as nothing more than a fancy wrapper for game points (since you need x monsters to unlock the next level). Try to think of a way of incorporating the monsters into the actual gameplay. Like, you could ride one of your monsters to achieve greater speed, precision, jump height, defense against obstacles, or any other power that depends on the monster. Then, by breeding monsters, you combine these powers, or something along those lines.

I dunno, make them a more integral part of the game rather than just be a useless carrot at the end of the stick.

Xaan