Add creature ranks

[jameshallam93]

Idea for a feature - creature experience/ranking up

Separate to the evolution levelling up, experience is gained through killing other creatures (no of kills or amount of damage caused)

Has a lesser effect than evolution (to account for the fact that it's a passive effect), but would create an extra level of strategy/decision making (keep long term, ranked pieces vs buy new, more base-powerful piece)

Accounts for the fact that early game pieces tend to become less and less relevant to gameplay as higher-level pieces get added to the deck.

Implementation strategy:-

• Begin by adding state for either damage dealt or number of pieces killed for each created piece
• Create temporary database field, average (damage dealt/pieces killed) for each piece, have stats from all pieces uploaded after every match
• After sufficient data is collected, work out appropriate ranking system based on averages (find x and y, where: multiply all stats by 1.x every rank up, where 1.x does not exceed evolutionary boost, and 1 rank up === y number of kills/y damage dealt, where y increases after each rank up)
• Add exp bar to piece images (similar to health bar), add logic to rank up creatures up on meeting experience requirements.
• (Possible future feature) - add new abilities with each rank up/3 rank ups etc. (i.e. area attack, rage, healing, etc.)

Pros:

• Creates a sense of loyalty to creatures that users have been using for a long time
• Adds new gameplay objectives and creates additional strategic possibilities.
• Possibility for new BOT trait (loyal vs fickle, where loyal bots try and keep the same pieces and fickle bots replace for better base-stat pieces)

Cons:

• Will be difficult to balance vs evolution/buying new pieces - i.e. hard to make sure that it isn't overpowered or underpowered compared to other strategies
• Need to find space in UI for all new elements (exp bar, rank (separate to evolution level)
• Would need to expand BOT AI to include decision making relating to ranking up.