Game jams are very good for coming up with ideas on a quick schedule, like said in above comments.
I know that looking at games for ideas might be effective, but do not fall into the trap of creating a "Counter strike, but with less weapons and one map" (no idea if this is accurate, never played CS). If you do that, then by definition if your development was perfect then you will get a game that is worse than your model.
If you don't fall into the trap shown above, but you still manage to create a viable plan by looking at other games (like said in above comments), then well done.