itch.io

Agree! I also decompiled it and I think the ideal strategy (in version 0.1.00 at least) is

• At first, only eat ¥10 packs of apple seeds and drink ¥150 unhealthy liquids (100% chance for each). This grind will let you survive, stay normal and save a lot of money or food items. You can even go down all 5 steps of the healthy route or fat route by varying the ratio between seeds and sodas. You can always starve to return to normal.
• Only other price point worth bothering with besides the aforementioned ¥10 and ¥150 is ¥100 (and ¥500 if you have that coin). This gives a good value-for-money of anomalies, healthy liquids and parasites. Healthy seeds and unhealthy liquids are best obtained in the previous point.
• After saving up enough items from it, eat a selected category at once to transform as you wish to the 3 stages of the other routes. 

Minor optimizations:

• Only eat on the street to waste less time not begging, although looking into your inventory next to the vending machine is the only place to see the front standing sprite.
• First operate the coin slot as many times as you need, then collect everything from the output tray by spam-clicking.