Relic Hunters Zero

Relic Hunter Zero is a free open source game. You start with 2 characters and can unlock 4 more through the game. The game consists of 4 areas, each with 3 levels, followed by a checkpoint and a boss fight. The "bounty" you collect by defeating enemies is retained throughout all playthroughs and can be used to retrieve items from checkpoints and permanently add them to your starting base for later playthroughs. The 8 relics in the game are each divided into 3 parts. You can find them randomly at the end of a stage or buy them at a checkpoint. Only 3 relics can be active at a time.