Prehistoric Mario contains some custom blocks. These blocks are stored in .dsc file. Leave this file in the exact directory with the ROM and it must have the same name as the ROM.

Also, sorry about one issue I can't fix. Due to SMW's limitation, you can place ONLY ONE checkpoint to a level. Since this hack is one giant level, checkpoint is ONLY on the boss preparation room. So, if you die, you will be at the very beginning.

Ignore the TIME UP! message. Because timer is set to 0, so the timer will never run out, it will display this message because you died with the timer at 0, and in the game's code, if you die with timer at 0, it will show this message.

Thank you for understanding