#40: Tenchu: Stealth Assassins - PS1
Stealth games were more fun when the AI was stupid. That's a hill I'm willing to die on. The guards in Tenchu aren't the brightest but it makes every stage a playground in figuring how to distract them and lure them to a gory bloody death. Add in plenty of tools at your disposal and 3 alternate layout for each map, you've got yourself some replay value right here.
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