updated with a few bug fixes and balance changes since the 7 days:
- if you win the game, remaining rings are worth 0.5 points each
- FAST: can take an instant step as well as instant attack, cost 0.5 rings
- BOUNCH: jump over enemies one by one
- DERVISH: attack one more tile but not through walls
- PHASER: can use to take a step through a wall without attacking
- hp changed a bit (there's not a 1hp hero giving unavoidable instant losses, but there's not the arbitrary healing from levelup either)