The closest game to Contra is Blazing Chrome. Here’s why:

1. **Gameplay and Spirit**:
– Blazing Chrome captures the spirit of the original Contra games, making it a strong contender for those looking for a game that feels like Contra.

2. **Mechanics and Controls**:
– It uses mechanics and controls similar to Contra, which aligns well with the Contra-like experience.

3. **Difficulty and Frustration Level**:
– It is fair in terms of difficulty, which is important for those who find Contra games frustratingly hard but still want a challenging experience.

4. **Additional Features**:
– The game includes a weapon upgrade system, adding an engaging element to the gameplay, similar to Contra’s upgrade system.

5. **Nostalgia and Homage**:
– It is developed by a studio known for its Contra resemblances, indicating a deep understanding and homage to the Contra genre.

Overall, Blazing Chrome is the closest game to Contra based on its gameplay, mechanics, and overall spirit.