Cebolla is easily the best monster to start off with. Even with low stats it already comes equipped with a healing move. So you can just repeat the process of attacking your opponent and healing when your HP is low.
An easy way to get the hard badge is to add variety to your stunts. Doing a combination of front flips, back flips, left and right spins will give you an automatic 10x multiplier. If you're lucky enough to enter into pilot mode, you get 20x multiplier; making it easy to get the badge. Check instructions to see the full list and always have your fingers on different arrow keys to perform different combos.
*Spoilers* oongiman's comment proves that he didn't truly understand the ending. Christina said at the end of the alternate timeline (where everyone survives) that she would travel back in time over and over again and causing the same events in the game until she found the universe in which her mother lives. When she does, she wouldn't have any reason to start the fire and kill the security guards since her mother is alive. Therefore in that universe no-one has to die, not even the two security guards.
When purchasing a skill or a task, it’s best to purchase it fully upgrade from the start. For example, if you choose to purchase a Level 2 Machine Gun, the next level will not subtract from the previous levels that you have acquired the item.
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