From StrategyWiki, the free strategy guide and walkthrough wiki

There are 12 achievements in Contra (arcade) worth a total of 200 .

Picture	Achievement	Description
	Armory	Collect 4 different weapon power-ups.	10
	Team Work	Score 100,000 points in an Xbox Live Co-op game.	10
	Untouchable	Get to the first tunnel without losing a life.	10
	Tunnel runner 1	Beat the first timed tunnel with 33 seconds or more left.	10
	Infiltration	Destroy the alien tower at the end of the water level.	15
	Tunnel runner 2	Beat the second timed tunnel with 55 seconds or more left.	15
	Well Equipped	Collect 3 different weapons in the second tunnel.	15
	Tough Guy	Get to the second tunnel without obtaining a single weapon upgrade.	20
	Proficient	Complete the second tunnel with a score of 100,000 or more in Arcade mode.	20
	Partnership	Complete the game in Xbox Live Co-op mode.	20
	Bulletproof	Complete the game in Arcade mode using only 1 credit.	25
	Full Assault	Complete the game in under 12 minutes.	30