5 Simple Game Mode Ideas

Death Match - start each game with X extra gold. X varies between 3k to 12k gold.

Lightning - 3x XP gain, no death timer

Darkness - Minion and tower grant NO vision. Cannot buy wards.

Jungle madness - no gold reward for killing minions. Jungle grants 3x gold on kill to WHOLE team.

Siege - 10 x Minion health, 1/2 frequency.