I don't really remember how all this works (I made this game 10 years ago), but after looking at my scripts, the ending is based on hours of play only. Minutes don't count, so 1 hour 59 minutes is 1 hour.
The breakdown is something like this:
- Hours of play <= 1
- Hours of play = 2
- Hours of play = 3
- Hours of play = 4
- Hours of play >= 5
There are also endings based on number of times you died
- Deathcount = 0
- Deathcount 1-2
- Deathcount 3-5
- Deathcount 6-9
- Deathcount 10+
Endings based on enemies killed
- Killcount == 8 (I don't remember how a person achieves this. Maybe only killing bosses?)
- Killount 9-100
- Killcount 100-250
- Killcount 250-400
- Killcount 400+
Endings for money spent
- Moneyspent < 12000
- Moneyspent 12000-13000
- Moneyspent 13000-14000
- Moneyspent 14000-15000
- Moneyspent 15000+