Power Pete is an overhead view 2D run and gun video game developed by Pangea Software and published by Interplay under the MacPlay brand name. It was released in 1995 and packaged with Mac OS 7 on new Macintosh Performa computers. (via Wikipedia)
The game mechanics of Power Pete
Free 2D MovementTraversalPlayer moves freely in 2D space with no forced scroll; camera follows player position.
Contact DamageCombatTouching an enemy or environmental hazard deals damage to the player without any explicit attack trigger from either party.
Hit Stun i-framesCombatTaking damage triggers a brief invincibility window during which further hits are ignored; the window length is a tunable design variable.
Real Time Action CombatCombatCombat resolves continuously in real time; player inputs compete directly with enemy behavior each frame.
Weapon SwitchingCombatPlayer carries multiple discrete weapons with different properties; active weapon is selected from inventory.
Ammo ManagementResourceWeapons have finite ammunition tracked separately from weapon ownership; running dry forces behavioral change.
Lives SystemResourcePlayer has a finite number of attempts; losing all lives resets progress to a defined point or ends the game.
Key LockProgressionA specific named item in inventory unlocks a specific named obstacle in a one-to-one correspondence; item is consumed.
Permanent PowerupProgressionAcquiring an item or ability permanently increases a player capability that persists through death and save/load.
Tile Map WorldWorldWorld is built from a grid of discrete terrain tiles; position on the grid is the primary navigation primitive.
Wave SpawningSimulationEnemies appear in scripted or procedural groups at intervals; surviving each wave is the primary challenge loop.
Each mechanic links to how to build it in Godot, with the retro games that share it.
Study the source
Open-source port (CC-BY-NC-SA-4.0). Re-released as Mighty Mike; Pangea put source + assets under CC-BY-NC-SA, so the jorio port is a complete, readable game. https://github.com/jorio/MightyMike