Add Adventure Mode

[psturmfels]

Currently, the game only posses a classic mode: Blocks fall from the sky, Lava rises from the ground, and the user attempts to avoid getting crushed or burned while climbing as high as possible.

I'd like to add a more amped-up version of the game that includes the following:

• [ ] Spendables, as discussed in the Game Center issue #3. I want to see different skins that may give the mellow certain advantages or properties, items or powerups that have to be purchased before they are seen in-game, different game modes to unlock etc.
• [x] Power-ups: already mentioned above, I want this game mode to have power-ups that enhance the user's experience of the game. Some power-up ideas include: temporary double jump ability, temporary jetpack, time-slow, extra life? etc.
• [x] Different types of blocks: Currently the game has a single type of block which is solid all the way through. I'd like to add other blocks, such as ones that are only solid if you jump on top of them, blocks that can be broken by hitting the bottom of them etc.
• [ ] Environmental Hazards: Think spikes, slippery ice on blocks, sticky glue on blocks
• [ ] Monsters: Flying monsters or grounded monsters that can be attacked and killed for currency, monsters swimming in the lava that leap out if they get close etc.
• [ ] BOSS BATTLES!!!!

[psturmfels]

I'm going to close this. It's as good as I want it to be.